Before you shoo me off to the newbie board, let me tell you I had a session the other day with a provider who was unaware that oils tend to disintegrate latex products--and she was far from being a newbie.  I had assumed this vital bit of chemistry was pretty universally known in our little world. I was wrong.  No mishap at the session, but it was a teachable moment.  Watch out for this problem and spread the word about it.