Prochem D456-4 Professional Tile & Grout Cleaner - Industrial Strength Deep Cleaning Formula for Tough Stains (4 Pack, 1 Gallon Each) - Perfect for Bathroom, Kitchen & Commercial Tile Floors

?? excellent productI used it to keep a shower. They say to dilute it. Well I used 50/50 mix with water in a small cereal bowl, then I applied it on the tile with a paint brush and let it on for 20 min. Used gloves, goggles and mouth mask (smells real bad; if you have windows open them, otherwise have a ventilator on). Also wear long sleeve shirt and long pants so you don't get any drop on your skin. After 20 min I scrubbed the tile with a tough brush and rinsed with water. I took some serious scrubbing to get it clean like new. Next time I will use 100%.In Europe we have much strong substances to clean tile. You apply with the brush, wait 5 min and then you just rinse it with water. No scrubbing. This thing is not even close to those substances. I guess you cannot sell those concentrations for the retail market in the US.Well it works but I will do dome workout scrubbing the tile.Breaks up grease and oils effortlessly. No need full dilution. 10oz per gal is all that is needed. Smells wonderful. My customers love the results.Finally something that cleans my grout well! I used this with my orbiter and a green brush and my grout looks great. Just rinsing the floor is a pain.Cleans very well and with only medium effort. Cleaning the solution off the tile when done was the biggest part of the work.Used a grout brush on an extension which helped allot.great productDon’t know how this stuff works, it was damaged in shipping and spilled in the box. Waste of money.Didn't work, waste of money.