Does 35% carbamide peroxide teeth whitening really work?

I have got myself some 35% carbamide peroxide and some mouth trays from online. Its meant to be great teeth whitener. Ive been instructed to wear it every other day for 5 mins and then increase to 10 if I dont get sensitivity. Ive tried it once for 5 mins. It stinks your gums but once its off its fine. Anyone used this and does it actually work? and if so how many 10 minute sessions will it take? Thanks
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i'm not sure about that but i use hydrogen peroxide and it works really good for me
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