What some have done for facial scars, moles, bumps, etc, is to soak a band aid with castor oil and apply it to the problem area. Many have had success in clearing them up. See the link below for a CureZone testimonial. This stuff is ugly to get if off of anything. I was doing castor oil packs and inadveretently got a few drops on a pair of sweat pants. I've pre-wash sprayed and worked the spots, they've been through the laundry twice, and I can still see the castor oil. But the benefits far outweigh the downsides.
http://curezone.com/forums/fm.asp?i=617584#i
I have a rather reasonable local supplier of the expeller pressed castor oil so I have lots on hand. I freeze any excess and keep just enough soluble for the packs. But, I've had thoughts of swishing with it. You sure don't want to swallow it, or if you do, stay close to a john.
Anyone ever tried it?