Twonk?

Someone has asked me what exactly a twonk is. For his benefit, I suggested the following:
1 twonk is roughly equivalent to a plonker.
it's worth half a prat, or one-eighth of a moron.
there are ten twonks to a git, and twenty to an arsehole.
one wanker buys you fifteen twonks, except where it is used in a friendly manner, in which case it only gets nine. There are also only nine twonks to a prick.
Fuckwit and cocksucker trade at a massive one hundred twonks, while dicksplash counts for sixty.
its value against sheepshaggers and goatfuckers is subject to regional variation.
This is, of course, all highly subjective.

I'm thinking of setting up the IN-DEX, or insults index, to register international trading on insults.