This acid-based cleaner is built with new technology in surfactants and other cleaning agents to rapidly clean and brighten tile and grout.  If the tile and grout are heavily encrusted with soil or have had floor finish applied, they should first be cleaned and stripped.  After rinsing the surface, apply Tile and Grout Restorer directly to the surface with a sponge or mop.  Allow this to dwell.  Rinse the surface with clear water.