Adding water: According to different external washing parts, choose the appropriate amount of water to add. Generally, the amount of water to add for external washing should be large, maybe 5 to 10 pounds of water Utensils: It is better to choose stainless steel pot or basin because of the large capacity and easy to operate. Decoction method: First place the drug in a container, add cold water and soak for 30 minutes, then put the lid on the fire to heat the decoction. First decoct with martial fire, bring to a boil and then decoct with civil fire. During the decoction process, pay attention to moderate stirring to avoid paste and also to improve the decoction rate of the active ingredients of the drug. However, the lid of the pot should not be opened too frequently to minimize the loss of volatile components. After boiling and decocting for 10 minutes on a civilian fire, strain the first decoction; then heat an appropriate amount of water and decoct according to the above method to take the second decoction. Mix the two liquids well. Washing method: Generally, one pair of external medicine is used for two days and twice a day, that is: one pair of medicine can be washed four times. The first time the boiled solution will be warm, (not recommended hot wash) and then the hands and feet or body invade the solution, each wash 15 to 20 minutes, wash can be washed off with warm water, and then save the solution for the next backup. The second, third and fourth time to boil the liquid for 5 minutes, let it warm up and then wash. The temperature of the solution: in general the temperature of the solution should not be too high when washing, to tolerate as appropriate, about 35-40 degrees. If you want to chaps eczema skin hypertrophy, flat warts or common warts wash when the higher the temperature the better, do not burn.