Is it me or is that punchline not even crass? The wording the article uses to allude to it is equally crass, as far as I'm concerned (so what was the point of not including it?).
Agreed, I don't know what 'it involves asking a sex worker' spares us over that. Nor why we want to be spared in an article on 'jokes that have made people laugh for thousands of years' even if it were worse!