Probably not that relevant, but re 'tonguing' another source might have been something to do with shore whaling in South Australia. I have read that the local orca population had an interesting relationship with the whalers. The orca would drive the whales (can't remember which species) onto shore and their reward was their favoured delicacy, the tongue of the whale, which the whalers cut out and threw to the orca.

Also somebody said earlier that this was the only NZ song to catch on in tradition. I remember 'Davy Lowston' being sung a lot in the 60s, miserable bloody thing that it is, but it came from the same book by Colquhoun.