Brick & Mortar Cleaner is a breakthrough in cleaning masonry. It has the cleaning power of muriatic (hydrochloric) acid, yet when used as directed, it won’t produce toxic fumes or cause burns. Now you can have the cleaning performance of a powerful acid cleaner with an unprecedented level of safety to users and surrounding surfaces. Brick & Mortar Cleaner safely removes most stains from masonry — including rust, efflorescence, and mortar splatter. It won’t blacken, streak, or damage metals such as the aluminum used in chimney flashings. To ensure results, try in an inconspicuous area before general cleaning. Brick & Mortar Cleaner can be used full strength for tough jobs or diluted for lighter cleaning.