It's not a surprise that you've never tried it. The only thing I found on the internet was some guy experimenting with it. The only thing he really said that was useful is that it doesn't eat away on the foam. I think I'll try it out sometime, maybe on another costume though. A friend of mine who's quite experienced in cosplay thinks it'll be brittle and break if the foam bends. An alternative that I've thought about is PlastiDip. Primer AND it makes the foam a bit more sturdy
I'll of course post some photos here on cosplay.com of the finished costume, but that won't be until summer!
Thanks for your reply