My friend told me one folk tradition she and her sister used to do as children. They would sit on the edge of a pond and stick their feet in the shallow water. After a while the minnows would come by and they would start biting at their feet, removing the dead skin.
We were watching a documentary on sea life and she volunteered this tradition. She claimed it feels like small pokes and was not painful at all. She said that the practice was also used by Asian spas, which would stick your feet in buckets of water with minnows in them.
The process seems to be an at home beauty solution which incorporates nature. It’s much cheaper, although somewhat more inconvenient that buying something to exfoliate your feet for you or paying for a spa visit. It makes sense that this originated as an eastern tradition since eastern medicine is known for incorporating natural remedies. It is interesting that it was adapted as a practice for children since it is also almost a daredevil game because it places children in a much closer relationship with nature than they would normally be. Minnows are not inherently dangerous but using them to clean your feet you are mastering nature.