I've done a search through my cupboards for anything looking like hydrogen peroxide but all I cam up with was bleach, and that doesn't have anything written on it saying what was in it. I also found a powder bleach that said it doesn't contain chlorine bleach. I live in Australia so it it possible this stuff is hydrogen peroxide? I just don't want to soak my cup in (diluted) anything without knowing if its safe for the silicone and for me. Is that absolutely the only thing I can use to get stains out of my cup?