soclean neutralizing cpap pre-wash, fragrance-free, dye-free, compatible with all washable cpap equipment, 8 ounce bottle soclean the neutralizing pre-wash is used for initial soclean setup. it is important to use the neutralizing pre-wash to hand-wash your pap equipment before you connect your soclean for the first time. the pre-wash is a fragrance-free, dye-free soap that neutralizes any odors and scents on your pap equipment.