PLEASE READ: If you buy Corte*Clean® from a retailer, make sure it is as fresh as possible by checking the "Best If Used By:" date on the back of every bag! Like most cleaning chemicals, the fresher Corte*Clean® is, the better & faster it works, especially when using Corte*Clean® for the first time, cleaning neglected composites that are saturated with deep tannin, grease, oil, rust or other common stains, particularly deeply rooted mold stains, or where other cleaning chemicals have been previously used, such as those that contain sodium hypochlorite, acids or phosphates! If Corte*Clean® is beyond the "Best If Used By:" date or is hard, and the product is not fluid, because it wasn't properly stored, in a "dry, cool area out of direct sunlight", DO NOT PURCHASE IT! You likely won't be satisfied with its results! Retailers not properly storing or rotating inventories is a serious problem for most cleaning products, including Corte*Clean®! Be warned, Corte*Clean® in round plastic containers with blue caps is extremely old & will likely not remove difficult stains, especially if the product has a crust layer on top, turned yellow in color or is hard in the container!