To save trouble and be hygienic, simple yogurt or honey will suffice. If egg white or yolk comes into contact with ants, cockroaches, etc. somewhere else in the house! There is also a very cheap method. Vitamin C costs more than one yuan a bottle. Use a small cap to fill it with cold water, put more than ten tablets of it, and let the skin absorb it after it dissolves! Or just turn the tablets into powder, add a few drops of water to make a paste and apply it on your face. Leave it on your hands, arms or other parts of the body for more than half an hour to let it be absorbed by the skin! Same goes for lemonade! Or just smear the thick layer of yogurt on your face. In fact, milk has no whitening effect. It's just because of psychological factors that it makes you whiter! If you want speed, it is far faster than just lemon juice mixed with a little water! Remember to leave it on for half an hour! It is good to boil Psoralen in water and apply it wetly to refine pores and whiten it.