I was at this thing called Blobfest over the weekend in Phoenixville, PA, and at one part they called on stage three women and three men and had them pair off and then mummify each other. It was just toilet paper, so it wasn't exactly expert bondage, but interestingly enough, all three pairs wrapped the mouths to stimulate gags.
I'm pretty sure they do this every year, so if you're ever near Phoenixville in the summer, stop on by!