Folding Vs Scrunching - An Empirical Test?

A recent comment on this blog suggested an empirical test to determine finally which is best, scrunching or folding? The anonymous contributor wrote:

'Firstly, we all need to agree that wiping your bum has one sole purpose; to clean it. So, to test this, find an uneven surface (as much resembly as possible to a bumhole) and place something with a similar texture of poo on it (porridge for example). Now, try to clean the uneven surface using once the wipe-with-folded-paper approach and once the dip-with-scrunched-paper approach. Which one was most efficient?'

Essentially you are trying to recreate the wiping conditions without actually having to wipe a real dirty bottom.

The idea of using something like porridge seems sensible but I'm not sure what could be used as a bottom substitute? It would need to be very close to an actual bottom for it to be a fair test.