I honestly don't know Beth. Barefoot is the expert on oregano. I hadn't heard anything about it either way until I met Barefoot. He say's it great.
The best soaking bath to take is with the himalain salts or the Celtic salts. Also try a bath with oatmeal. No, not the kind you eat but they sell oatmeal soaps and bathing salts that make the skin smooth as silk. Really good for the skin too.
But the salt bath with seasalts does wonderful things for you. Its a great antiparasite protocol and helps balance the electronics of the body.
Cheyenne or oregano oil as a bath? I don't know, give it a try, see what you think and let the rest of us know.