Of British-English origin, the meaningless bantering phrase how are you off for soap? originated in the following satirical print by William Elmes (floruit 1804-1816), published in London on 21st June 1816 by Thomas Tegg (1776-1846):
—© The Trustees of the British Museum, released under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) Licence:
Titled How are you off for soap, this print depicts a young woman standing over a wash-tub and raising her hands in astonishment to see a little man standing waist-deep in the soapsuds. This man is saying with a smile: “here am I!! Betty!! how are you off for Soap.” She answers: “Lord!! Mr Vansittart!!—who could have thought of seeing You in the Washing Tub.” 1
1 The British politician Nicholas Vansittart (1766-1851), 1st Baron Bexley, was the Chancellor of the Exchequer from 12th May 1812 to 31st January 1823.
In Catalogue of Political and Personal Satires Preserved in the Department of Prints and Drawings in the British Museum – Vol. IX – 1811—1819 ([London]: Printed by order of the Trustees, 1949), the British historian Mary Dorothy George (1878-1971) explained that this print is:
A satire on the Act for altering the excise on hard soap, brought in unobtrusively in May  as a regulating Act only (to protect the whale fisheries), but producing an estimated revenue of £150,000 and an increase in excise duty of 8 and 9s. a cwt., or a charge per annum of 3d. a head. It was attacked by Brougham. 2
2 The British politician Henry Peter Brougham (1778-1868), 1st Baron Brougham and Vaux, was then Member of Parliament for Winchelsea.
The Scottish economist William Smart (1853-1915) mentioned the print in a footnote to Soap Duties – 1816, published in Economic Annals of the Nineteenth Century 1801—1820 (London: MacMillan and Co., 1910):
We hear of the Soap Excise first at the report stage, when a member became aware that an important Bill had advanced so far without observation and without being printed. One learns that, as proposed, it was an additional duty on hard soap, and that the first objection came from those who used soap in large quantities, particularly the woollen manufacturers. The Chancellor of the Exchequer then promised to remedy this by imposing equal duties on soft soap. At once it was pointed out that this was now a measure of taxation and bore heavily on the consumers, especially the lower classes. The Chancellor explained that the new duty originated in a desire to give encouragement to the whale fisheries, but he had subsequently thought that “it might be useful as a measure of revenue.” It would raise about £150,000, and he commended the tax as “a very little one”; it would fall very lightly on the public, amounting to no more than threepence per head of the population of the kingdom. Sir M. W. Ridley said that he might feel no objection to it as protection, although it would considerably injure the kelp trade, but he did object to it as a finance measure. Brougham scornfully said that this was the way in which measures slipped imperceptibly through the House, and people were prevented from considering their interests properly. “Straw was laid on straw, till the last straw broke the mare’s back. Additional taxation on soap, even at the lowest rate, must increase the price of labour. Had the tax on salt been begun at its present figure of 15/- a bushel, it would not have been borne; but the practice was to begin low and then to advance, and to say that it was only threepence or fourpence of an increase. He hoped the House would pause before they passed a tax Bill on an article of necessity, for which the only defence was that the amount of the increase was small.” *
* This tax formed one of the quartet which, as a rule, had been excepted from the general rises in the excise duties. Pitt had, during his long career at the exchequer abstained from making any addition to the tax even in the darkest hour of the Great War (Dowell, History of Taxation, ii. 254). “Lor’, Mr. Vansittart,” said a caricature, “who would ever have thought of seeing you in the washing tub?”
The phrase how are you off for soap? then occurs in The Age (London, England):
1-: Of 5th May 1833:
MAY-DAY IN THE MORNING.
This time-honoured festival was peculiarly festive on the 1st of May, in the year of our Lord 1833 […]. Here, then, is the reason why Members of Parliament, having made fools of themselves in every other conceivable way, resolved on crowning the wreath of their absurdities with a May-flower […]. The appearance cut by these distinguished personages—the freaks and follies perpetrated by them—the extraordinary zest of their conversation, and the enormous melody of their songs, will be found in the following “beautifully dreadful” narrative.
The following turn was then given to the conversation by Brougham:—
Brougham.—Pray, Althorp, how came you to bungle the budget so abominably? And then lngilby’s motion! Surely a little judicious humbug would have managed that matter.
Althorp.—It does not fall to the lot of every man to be so great a master in the art of humbug as my Lord Brougham. What I could do in this way I have done; and I am prepared to resign.
Grey.—Prepared to do what?
Grey.—Why look you, my dear Althorp, although I might resign myself to your resignation, yet knowing that it would lead to a general break up, I must impress upon you the necessity of our having the use of your candour, honesty, bonhommie—and all the rest of it, for some time longer.
Althorp.—Well, then, keep Brougham quiet, and don’t let Stanley call me nick-names. He may call me “Old Mumble”—better be that than “Young Grumble,” as all the world knows him to be.
Grey.—Oh, let that drop. By the way, Palmerston, how go on matters in the East?
Palmerston.—Why—aw—I’ve seen no one for two days.
Brougham.—Don’t twaddle! Is Hobhouse to come in again?
Ellice—I should think so. Burdett can do as he likes. If so, it was a good bit of clap-trap on the part of Hobby.
Brougham.—Now I think his resignation a piece of very short-sighted humbug. It would have been a good move in my time. But the march of intellect—
Althorp.—And the repeal of the duty on tiles—
Brougham.—True, old fellow, how are you off for soap? As I was saying, Hobhouse is an ass.
Reeve.—And so are you all honourable asses, to be talking “shop,” after this fashion, while the grog and the Venusses are waiting.
Upon which they all fell a-drinking to the tune of “We won’t go home till morning”—which they did not accordingly.
2-: Of 9th June 1833:
THE SPEAKER’S GALLERY.—No. I.
[…] Mr. Manners Sutton has, in anticipation of his approaching retirement from the fatigues of office, fitted up a gallery, in which he has placed full-length portraits of the most remarkable men who sat in the two last Parliaments […].
[…] At either side of [the portrait of Mr. Manners Sutton himself], but lower on the wall, and of a smaller size, hang portraits of the whippers-in—Whig and Tory—Mr. William Holmes on the right, Duncannon on the left. […]
Mr. Holmes […] is drawn with a countenance radiant with joy, as though it were after having whipped-in a smashing majority. He has to perfection that picaro air which won Gil Blas’ heart for Scipio. His left eye is half-cocked, and his tongue is inserted in his right cheek. He is leaning back on his seat, with his feet resting on the back of that before him: the thumb and little finger of the right hand are spread abroad, and as wide as possible asunder. He is evidently restrained only by the presence in which he is, from applying the thumb to the tip of his nose, and shouting to the discomfited-Duncannon, “How are you off for soap?” The defeated Whig looks as woe-begone as it is possible for a wooden-man to appear. He is sitting bolt-upright: the face bears an entire resemblance to Punch’s, as he figures in the puppet-shows. There is the same “lengthiness”—the same style of unvarying non-expression. The peculiar hue and appearance of the neckcloth, too, is depicted—the roll of dingy cambric coiled like a rope about the neck, and forming an essential accessory in a painting either of Punch or Lord Duncannon.
3-: Of 1st September 1833 (this text also contains the variant how are you off for tigers?):
THE JUNIOR UNITED SERVICE CLUB.
These ci-devant youngsters are in the devil’s own commotion. Here’s all about it:—
A general meeting is called on the subject of the Cook—and when we inform our readers that the gallant Juniors have a knack of eating a dinner and paying for it as a lunch, thus doing the Club out of the charge for extras, &c., we need scarcely add, that no subject under heaven could more deeply concern them than the said subject of the Cook. […]
General Sir John Elley then rose and said,—Mr. Chairman and Brother Officers; on a matter so important to us all as the conduct of the cook, it can hardly be necessary that I should do more than mention the facts to rivet your attention—
Here that handsome youngster, Desborough, interrupted Sir John by requesting him not to shake his head. Sir John appealed to the Chairman—who appealed to Desborough—who thus replied:—
I really, Mr. Chairman, do conceive, that the conduct of Sir John in accompanying his affirmations with negative noddle-shakings, is calculated to perplex the Meeting, and to prevent our coming to a sound conclusion. If, indeed, Sir John would shake his head and say nothing, after the Lord Burleigh fashion, we might understand him; but saying one thing and intimating another, is what we cannot submit to.
Sir John, glowing with rage, roared out, Who the devil are you, Sir, that dare to address me thus?—(Loud cries of Hear and Order!) —amidst which
General Shain (or Swain) rose and said—Gracious God! young man, you really surprise me! Do you know that Sir John Elley is an officer of distinguished high military rank—a sort of a kind of a Hospadar?—(Loud laughter, and cries of, How are you off for tigers?)—which seemed to annoy the Gallant General; for, blubbering with vexation, he shouted—I never saw a tiger in the whole course of my life, except Lord Ranelagh.
Barry O’Meara observed, that though nothing remained to be said on the subject, he would observe, that Lucien Buonaparte was a great judge of cookery. He also was fortunate enough to agree with the Prince of Canino on the subject of fat women. He thought the cook had made a rare hash of it—yet, as he was a broth of a boy, he thought that they should not roast him too severely, lest he might be tempted to retaliate by giving every member an “intestine broil” in the shape of over-deviled kidneys.—(Applause.)
Captain Doran then rose; but was assailed with such loud and general cries of “How are you off for soap?” that he sat down “all in the suds!”
The phrase how are you off for soap? occurs in the following passage from Peter Simple (London: Saunders and Otley, 1834), by the British naval officer and novelist Frederick Marryat (1792-1848):
I had arrived opposite a place called Sally Port, when a young lady very nicely dressed, looked at me very hard and said, “Well, Reefer, how are you off for soap?” I was astonished at the question, and more so at the interest which she seemed to take in my affairs. I answered, “Thank you, I am very well off; I have four cakes of Windsor, and two bars of yellow for washing.” She laughed at my reply, and asked me whether I would walk home and take a bit of dinner with her. I was astonished at this polite offer, which my modesty induced me to ascribe more to my uniform than to my own merits, and, as I felt no inclination to refuse the compliment, I said that I should be most happy. I thought I might venture to offer my arm, which she accepted, and we proceeded up High Street on our way to her home.