Windex can treat gray nails. Windex is composed of menthol, camphor, methyl salicylate, eucalyptus oil, clove oil, etc. It has the effect of clearing heat and detoxifying, analgesic, resolving bruises and swelling, and sterilizing. You can soak the affected nails in rice vinegar water first, and then remove the necrotic nails with scissors. Apply two drops of Windex to the affected area and massage until completely absorbed, once or twice a day. You can also apply topical medications such as terbinafine hydrochloride ointment and ketoconazole cream to the affected area after absorption.