Other doctors have had plenty of informal success with the power of suggestion. Says Christopher McEwen, M.D., "I've treated a couple of kids who could not tolerate freezing, which is how we usually remove warts. So I gave them a harmless substance to use and impressed upon them that it was a very strong medicine that would knock out the warts. And it worked." Strong belief in a cure may also explain the continued popularity of such offbeat, old-fashioned folk remedies as rubbing the wart with a penny and then burying the penny under the porch.