If you have ever run with a rock in your shoe, you know just how painful a little pebble can be.

Sometimes a callus forms in a way that it gets rock hard and starts to get embedded in the skin.

Painful calluses can literally feel like a rock taped to your foot. The problem is that callus removal pads don’t work.

Using a pumice stone to shave down the surface of the callus doesn’t really help much either.