Pudding/Mud-wrestling ?

Hi Folks- i´m planning on making a pudding or mud-wrestling on my next birthday but I am still not sure which substance would be good for that-
the pudding at the the supermarket is too expensive to fill my small (plastic)pool with and so I ask if you maybe know a good substance that is not too expensive which I could fill into it? or do you know what the big organisations use for their wrestling-events ?? mostly i´d like a really thick and gooey substance
Any hints and clues would be great -
the pudding at the the supermarket is too expensive to fill my small (plastic)pool with and so I ask if you maybe know a good substance that is not too expensive which I could fill into it? or do you know what the big organisations use for their wrestling-events ?? mostly i´d like a really thick and gooey substance

Any hints and clues would be great -