Sorry Jon... this is just one of those songs that it's really hard to dance around the lyrics... kinda like "Eskimo Nell"...But I've also heard the carrot... Depending on who's singing it, how drunk the crowd is, and how drunk the singer is, I've heard everything from very polite metaphor to terminology that I've had to look up later...
One of my favorite pub versions is done as a drinking song, where the band one by one grabs a pint and guzzles it while the band holds the note on "as drunk as drunk can be____________". A few hardy souls in the crowd usually try to match the band drink for drink... with the usual humouros results (Ever seen someone try and order a beer after downing 5-7 pints in under 5 minutes? It's amusing)
M