Tile is almost always the easy part. The difficult part is the grout lines. Some have not been cleaned for years and porous grout can be packed with oily soils. If the floor has been abused, use plenty of dwell time and let the Viper Venom doe its job. Apply heavy and wait 10 to 15 minutes or sometimes longer. Agitation will still be needed in some spots, but it is better for the chemical to do the heavy work.