I've had a hairdresser use plastic wrap before. She rolled my hair, wrapped it, covered it in plastic wrap and put me under a dryer. The plastic wrap loosens the curl, but keeps the body in your hair.
I use plastic wrap sometimes if I wash and roll my hair and need to be somewhere the same day and want a smooth look with a little bump to the ends and a lot of body. If I wash at night, I just wrap and go to sleep and in the morning I have the same effect.