Slumber party prank aftermath...need help!?

I had a bunch of friends over last night to sleep over. Me included, it was six people total. In the days prior to the party, we'd all teased each other, saying we were gonna prank whoever fell asleep first. It was all in fun; none of us thought anyone would actually do anything. Well, I was wrong. When we woke up this morning, two of my friends found that someone had glued their hands together while they slept. This is some pretty serious stuff. We've been trying all day to get them separated. Nail polish remover isn't doing anything. No one will admit to having done this, so we have no idea what kind of glue this is or what the solvent might be? We can't send them home holding hands obviously, so any advice on how to get them apart? Aside from the hospital? And how can we find out which girl did this?!?