I couldn't resist. I've seen the videos and the pictures and I had to try it myself. Microwave a fresh bar of Ivory soap (no substitutions!) for about 2 minutes.
My bar of soap wasn't quite as fresh as it should have been but you get the idea. Note to all who want to do this you will have a very strong soapy smell afterwards, if you don't want it to stick around put your experiment outside immediately following your fun.