This spring, the Medical Marijuana Caregivers of Maine joined the usual coalition of anti-pot forces that includes active law-enforcement groups, social conservatives and public health advocates to oppose a state bill that would legalize possession of small quantities of the drug.
And it's not a good idea to use it as mouthwash. Hydrogen peroxide (in dilute form) is used as a tooth whitener (check the active ingredients on those gel-based tooth whiteners, they usually use H2O2). It also has the side effect of turning your gums pale temporarily, though it wears off in a few hours.
Most tooth whiteners use one of two chemical agents: carbamide peroxide or hydrogen peroxide (the same stuff that will bleach your hair). When used in the mouth, carbamide peroxide breaks down into hydrogen peroxide and urea, with hydrogen peroxide being the active whitening ingredient.