The tim-tams exist between the chest and the secret place. They rest atop the bottom portion of the rib cage, one on either side. Tim-tams are, by scientific standards, the most important part.
A sexual act performed between two people. Every Australian at some point in their life has consumed milk with TimTam's. You bite either end of the TimTam and use it like a straw, faily simple. Same principle applies to The Dirty TimTam. The Anus of an individual is filled with milk and sucked out with a TimTam like a straw by the other.
Shazza let me give her the Dirty TimTam the other night... tasted awesome till i sucked up a bit of poo.