My limited experience of this song/chant is something like:

Get 'em down, you Zulu warrior
Get 'em down, you Zulu chief, chief, chief, chief
Zumba, zumba, zumba, zay
(etc.)

and was sung in the rugby club bar after a game, with one of the players being coerced into removing his lower garments (don't ask, it's what rugby players do, or used to anyway, for relaxation) :-)

Is there a rugby player in the house who can confirm this? It's ages since I heard it or even went into a rugby club, so it may not be done any more. Anyone know?