Stain Devils are individually formulated, stain removal instructions may change from formula to formula. Stain Devils formula should completely remove your stain, the time required may vary from immediately to several minutes or more. Combination stains. This can make stain removal a bit more complicated and may require more than one Stain Devils formula to remove it completely. But if you value your garment, it's worth the extra time. Stain Devils are safe and effective on washable and water-safe fabrics, excluding silk, acetate, carpeting, or upholstery. Every formula is dermatologically tested to be safe for your hands and environmentally friendly for disposal