Curmudgeon here. To go back to Old Bones' original query, here's the comments of R.R. Terry in The Shanty Book.

This shanty differs from all others, as (a) it was sung tutti throughout; (b) it had only one verse, which wass sung over and over again; and (c) it was used for one operation, and one operation only, viz. bunting up the foresail or mainsail in furling.. In this operation the canvas of the sail was folded intensively until it formed a smooth conical bundle. This was called a bunt, and a strong collective effort ( at the word "boots") was required to get it on to the yard.

Although the same verse was subg over and over again, very occasionally a different text would be substituted, whwich was treated in the same manner. Capt. Whall gives two alternatives which were sometimes used:

We'll all drink brandy and gin and We'll all shave under the chin.

Mr. Morley Roberts also told me that a variant in his ship was -- We'll all throw dirt at the cook!

Good songs to all -- Tom