What stone can play a health care role when stepping on your feet?

Because there are many acupoints on the soles of the feet, any stone that can stimulate the acupoints can probably be used, depending on how to deal with the damage of stones to the soles of the feet. Pebbles are very good stones. Stones should not be too big or too small. They should be arranged according to certain rules. Try to have some round stones instead of sharp ones. To avoid cutting the soles of your feet!