Years ago I had some pinworms and read up about them. They have to come out of the anal orifice to lay their eggs, at night. So I decided to whammy their plans. I kept the orifice slathered in Noxzema, as much as wouldn't go thru my underpants. It seemed to me they would not be able to breed, or even live in that environment. I kept this up for about 2 weeks as it is easy to get reinfected from eggs in the environment. They have not come back and it has been years.