Nobody ever went broke underestimating the taste of the American public.

I was complaining the other day about not being able to use tooth-whitening strips, and my father informed me that there's a whitening mouthwash which is much easier to use than the strips. So I picked some up this afternoon on the way home from work, and I tried it out just now, and oh man, I did note when I bought it that it's hydrogen-peroxide-based, but it didn't actually occur to me that this stuff was going to foam in my mouth until I was oozing froth from all facial orifices.

Has anyone ever used this nightmarish stuff before? Is there a trick to it? Because otherwise I think I'm just going to have to live with teeth that are not perfectly white. I don't know if my delicate constitution can withstand swishing H₂O₂ for a minute at a time.