Tip! Drano takes off any kind of concrete stain! Just pour it on and literally in like 2 minutes it's bright white again! Whether it's that gross green mold, oil, that weathered black look..takes it all out.
INEXPENSIVE CLEANING SECRET: a little water or vinegar will lift even the most stubborn stains; cleans grout, mold & mildew stains, burner pans, porcelain tubs; also nature's bleaching agent. It is an acid, but is not harmful. Use a few tablespoons of cream of tartar with hot water or hydrogen peroxide to clean aluminum pans, rusty drains or stains. Add lemon juice to COT to clean copper. Add glycerin with few tsp COT & makes spray-&-wash fabric stain remover. | best stuff