A Cure for Leg Cramps?

A dr who writes a daily column in our newspaper mentioned that many people have written to him claiming that a bar of soap under the sheet in the bed will prevent those awful leg cramps. Mom has had them since she was a teen, so she tried it. No kidding - she has not had a leg cramp in months! One night she awoke with her leg beginning to go into spasm, & realized that the soap had slipped to the other side of the bed. As soon as she put it back, the cramp disappeared. No one knows WHY this works, but it DOES. I think Dove & deoderant soaps were not acceptable. Mom uses Olay. She leaves the wrapper on as well. This dr is very bookish & rejects most natural remedies, but he states he cannot deny the responses with this treatment. Worth a try!