I've used peroxide with no problem
by Pat
(Oklahoma, USA)
I swish with peroxide (the kind you get at the store, 3%) about once every other week when I take a shower (so I don't get it on my clothes - it bleaches everything!) ... the only thing I've noticed is an odd aftertaste, but I used to have gum disease and now it's totally gone.
Plus my teeth are whiter too :)