Does anyone know where/if you can buy one of those hats you used to see on TV that was filled with foam but had a hole in the top. The poor victim would have his head covered in foam (usually getting pied to) and as they pulled the hat down on him it would squeeze foam through the hole and all over him?
Sorry it's hard to really explain it well. There are a couple of videos floating round with it but I can't find them to post them here to help.
The other half has actually volunteered to be foamed in public :-O
I attempted this for the clowns shoot I did. It was a fail but it did provide good experience for a second attempt.
The hat is easy - I just ordered a cheep costume hat online, then put a hole in the top (I think I used a hole-saw, but knife/scissors would work).
The mistake I made was using something too thick to flow well through the hole - I used whipped cream. I would suggest something light and fluffy like rabbits, or even whipped egg whites (seriously don't use rabbits - leave that to the magicians, they're trained for it).
Shaving foam will work. Used on as part of a (non-WAM) sketch some years back. it was a cheep plastic union flag hat - the sort that got sold a lot for jubiliees and royal weddings. Cut a hole with a pair of sissors about 2cm in diameter. The person putting the hat on the victim needs to push it down really quickly to get the foam to squirt out.