Stain remover begins removing tough mildew stains on contact. Spray or wipe directly onto surface to be treated, wait for stain to disappear, and then rinse thoroughly with fresh water. One application will remove most mildew stains, while stubborn stains may require a second application and light scrubbing. Ideal for use on poly, plastic, and fiberglass outdoor furniture, outdoor fabrics, and vinyl umbrellas. Buffered formula is tough on stains but won't harm stitching.