Clean and dry the surface as best you can. Then, give the Miracle Mold Stain Cleaner Gel tube a good shake for 5 to 10 seconds. When opening the product, completely remove the foil covering the cap before attaching the nozzle. To attach the nozzle, unscrew the nozzle cap from the end of the nozzle. Next, apply the gel evenly across the area of concern and leave it on for 3 to 5 hours.