Stop leg cramps or restless legs: Place soap under your sheets.
This advice definitely falls into the category of “there’s no science behind it, but people swear by it.” And it’s not likely to do any harm, so if you have regular nighttime leg cramps, give it a try:
Place an unwrapped bar of soap underneath your fitted bedsheet to stop nighttime leg cramps or ease restless leg syndrome.
It may be the placebo effect—you placed the soap so you expect it to work—or it may be some other reason. You can find plenty of people who swear by it, some of whom insist on specific brands of soap.
Leg cramps can be caused by dehydration or a lack of potassium, so making sure you’re well hydrated might help eliminate them, too. The bar of soap can’t hurt and might help—even if we never know why.