Woman in bubble bath
Hemera Technologies/AbleStock.com/Getty Images

When applied topically, the lactic acid in milk will gradually reduce skin's pigmentation, resulting in a lighter complexion. Overall results vary, but the book “1,001 Home Remedies and Natural Cures: From Your Kitchen and Garden" mentions that maximum results are achieved after three weeks of daily treatment. For most people, the maximum result is a lightening of skin complexion by approximately one-half of a shade. Once this effect has been achieved, milk must be topically applied at least twice per week to maintain the results.

Pour milk into a bowl. Any type of cow's milk or goat's milk will lighten your skin. However, buttermilk has the added benefit of leaving your skin soft and smooth after application, according to “1,001 Home Remedies and Natural Cures: From Your Kitchen and Garden." Microwave the milk for 30 seconds to warm the milk.

Soak the washcloth in the milk. Wring out some of the milk. The washcloth should be fully saturated with milk, but not dripping.

Massage the milk into the clean, dry skin you want to lighten with the washcloth. When the washcloth dries out, refresh its milk supply by dipping it in the bowl of milk. Following a shower is a desirable time to apply your milk treatment because your skin is clean. Wait until after you have applied your milk treatment to apply perfume or lotion to your skin.