Soap can contain magnesium, so another theory is that it may help with leg cramps caused by magnesium deficiency.

Which soap is high in magnesium?

Life-flo Magnesium Bar Soap | Super Concentrated with Calming Magnesium Chloride, Plus Coconut and Avocado Oils | 4.3oz.

Is there magnesium in soap?

This is because some soap contains magnesium, which has muscle relaxant properties and may ease restless legs symptoms.