Krud Kutter Metal Clean & Etch cleans & etches in one step. Cleans & prepares concrete, masonry & brick for coating, staining or sealing. Ideal for cleaning, degreasing & acid etching concrete floors, walls, basements, driveways, swimming pools, patios & containment areas prior to coating, staining or sealing. Safer & easier to use than muriatic acid, it creates a porous surface & provides the even profile & uniform appearance preferred for clear coating applications. Also removes efflorescence & neutralizes new concrete & new mortar joints. Earth-friendly.