Get the 35 % - 44% carbamide peroxide tube/syringes on ebay, they are cheap as chips, only use to for 30 mins a day, maybe even every other day, never leave them longer than 30 mins, unless you want to be in agony, the syringes are pretty good, you can get all your teeth, and use a mouth guard so your saliva doesnt mix with it, and it also protects your gums
be careful, or it will burn your gums, goes away, but do you really want to be sitting there for 30 mins with a gum on fire sensation
Also those crest 3D are okay, they are 10% hydrogen peroxide, i think that equals 35% percent carbamide peroxide, something like that
But those dont whiten all your teeth.
But if you truely want WHITE teeth, well ZooM WHITEING..