My M.D. father, family practice in the army, later a pathologist, would do what he had learned from other doctors: Put some dye in toothpaste, put it on the war

My M.D. father, family practice in the army, later a pathologist, would do what he had learned from other doctors: Put some dye in toothpaste, put it on the wart(s), bandage it, talk about what a miracle cure it was etc. He said it worked the few times he tried it. His M.D. son (my brother), partner in a pediatrics group, points out that placebos are ethically troublesome for doctors.