I can`t see that swilling your mouth out with a peroxide solution would make your teeth white. You have to put the peroxide against your teeth for quite a while. I haven`t looked at superscrimpers but there is no cheap way to whiten your teeth. I had mine done in South Africa (because I was there and it`s cheaper). I had a proper mould made and I was given a gel to use with the mould. It was called Opelescence and it was 20% carbamide peroxide. You have to be really carefull to place the gel into the right part of the mould so that it doesn`t go onto your gums. Most of these whitening agents make your enamel more porous and then the teeth can become even more stained because they will absorb more stains from tea, red wine etc.