Actually I'm not planning to wear a costume at the Escalade but -- according to the videos on youtube -- lots of people do. I was looking for stuff for a New Year's party and found this great shop mentioned on some forum. It's in Passage de Terraillet (Geneva). I've forgot the name of the shop XD but if you're looking for masks, wigs, ears, noses, body paint -- or anything even remotely like these -- this is the place to go.
Have fun! ;)