You mean the mute pad. It can be forcibly removed and mixed with mild detergents such as warm water and detergent to make solvent. Soak the mute pad in the bathtub for a few minutes. This helps to remove dirt, grease and odor. Wash the mute pad by hand with a soft cloth. After soaking for a few minutes, clean both sides of the mute pad with a soft cloth. Scrubbing should be thorough, and attention should be paid to the places where hands and feet contact most often. After washing, dry it with a towel and dry it in the shade.