It's my understanding that "harm none" includes yourself. I would suppose you can be a Wiccan and practice self-mutilation. There are many people in all religions who identify themselves as Christian, Muslim, etc and don't follow the tenants of those faiths. In my opinion, to be a Wiccan who is trying to follow the path and serve the Goddess, you must strive to harm none, including yourself. We will all fail at this from one time to another, but we must always be striving to improve.