1. Clean up the dirt on it when you first get it, and use a pick needle and brush. At this time, it is not recommended to brush oil, so as not to dirty walnuts or cause yin skin.

2. After brushing, you can play with your hands. Be careful not to see water, sweat, and the temperature difference is large.

3. You can brush some olive oil or walnut oil in winter or dry season. The method is to put oil drops in the palm of your hand, dip them in the brush with a brush, and dry them with a soft cloth after brushing. Walnuts are also cleaned in this way after they are dirty.