I first saw this performed by a group of people at the Newcastle (Australia) Folk Club back in the early 80's I think. I may have seen it a couple of times since then, and it always cracks me up too - especially the po-faced delivery. In at least one of the versions I saw Leadfingers' pointing over the shoulder gesture was used for "back".

It's possible that here in Oz someone brought it back from Vietnam, or that it came here from footy players, but it would be hard to track it back to find out who learned it from whom after all this time.

Helen