This might sound crazy but according to Dr. Mehmet Oz, host of "The Dr. Oz Show" sleeping with a bar of soap under your bed is not just a fantasy remedy. Many say it helps with "Restless Leg Syndrome" and could also help with insomnia.
A simple survey was done and 42% of respondents said it helped with their leg cramps and or insomnia. It is important to mention that survey respondents claimed that not all brands work. Specifically Dove and Dial were said to have no affects. Also lavender soap was said to have a soothing aromatherapy bonus in addition to relieving RLS.
Reference: Comella CL. Treatment of restless legs syndrome. Neurotherapeutics. 2014;11(1):177-187. doi:10.1007/s13311-013-0247-9