Ss with bilateral warts, treated randomly on one side or the other, then treating the other side. Control group of wait list subjects. This was used in some old studies using hypnosis to successfully reduce warts. Look this up because it points to a potent placebo effect in wart treatment. You might want to use the active drug on one side of the body in the experimental group and an indistinguishable non-treatment on the other, randomly selected.