If you want whiter teeth but not the hassle and expense of a teeth whitening treatment, grab a banana peel. Rub the inside of the peel against your teeth for 2 minutes. Wait 10 minutes, then brush with a dry toothbrush. The potassium, magnesium, and manganese in the peel will act as a natural bleaching agent. This will get absorbed into your teeth and lighten your stains while the brush buffs them away. In no time your smile will be whiter!