[Livia]

I get bleach from my hygienist, it's very mild and I use it about twice a year. She made a cast of my teeth and I got a kind of gumsheild... you put a tiny amount of bleach in it and sleep in it for a week or so. It works brilliantly. It cost about £250 and you just replace the bleach when you need to... although I'm quite stingy with it.