Instruction: Foot odor is caused by many sweat glands on the soles of feet, and it is easy to sweat. Besides water and salt, sweat also contains lactic acid and urea. In the case of sweating, bacteria on the feet multiply and decompose keratin, and urea and lactic acid in sweat will give off an unpleasant smell. It is suggested that 10- 15g alum should be added to the foot scalding water. After the alum is dissolved in water, the feet should be scalded for 15-20 minutes at a suitable water temperature, once every night, for 5 minutes continuously.