You can't. Wool products such as sweaters are not alkali-resistant. If it is washed with water, it is advisable to use neutral detergent without enzyme, and it is best to use special detergent for wool. Soap and washing powder are alkaline detergents, so it is recommended not to use them, let alone soak them all night. Otherwise, it will destroy the fiber and color of the clothes. Wool fabrics should not be bleached with chlorine-containing bleaching solution, but with oxygen-containing color; Squeeze and wash, avoid wringing, squeeze out water, spread it evenly and dry it in the shade or fold it in the shade; Wet plastic surgery or semi-dry plastic surgery can remove wrinkles and avoid sun exposure; Softening agents should be used to maintain soft hand feel and antistatic properties. Dark colors generally fade easily and should be washed separately.