Which is the best affordable Teeth Whitening products?

Hi everyone, i just wanted to ask, what are the best, most effective, and affordable teeth whitening products that can be purchased from a local pharmacy (not from any websites)? There are so many different kinds, i don't know which ones are good or not, which ones work or not, so yea i just wanted to ask for you opinion. P.S. I was thinking about trying the Listerine whitening pen because so far from what i have seen, it the cheapest teeth whitening product, have anyone tried it before? if so, how did it work out? Thanks
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in my opinion do try toothpaste or tooth whitening stuff from supermarkets or webstite as they wont help you , it all marketing strategy. the proven way is laser surgery. but the cheapest way is brushing rigoursly 2 or 3 times a day for 3 to 5mins.
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