For women, this armpit area should be much cleaner, because the armpit is a place where sweat glands are very developed. In the end, it may breed a lot of bacteria, and then it will cause odor, which is not very friendly to personal image. For the health of underarms, more care and cleaning can avoid bacterial reproduction and remove the odor of underarms.
Underarm pigmentation may be caused by sweat, especially for people with excessive armpit hair. Wash armpits with milk and salt (salt accounts for one thirtieth of milk). Keep it clean 1 week before the dirt can go away.
You can also use a towel, add soap and wash it several times. Simple and convenient. If it doesn't work, wash it with shower gel several times.