How to Thoroughly clean tile grout

In this video Rich explains how to maintain a grout and tile floor. He uses a chemical cleaner which he describes as a "grout-smart type product." For regular maintenance of the floor Rich recommends using only 1oz of the product per gallon of warm water but for really badly stained floors using up to 12oz per gallon of warm water. Rich mixes the chemical into his water then applies the mixture to the tile using an ordinary deck scrubber, he then uses an angled scrubber which has bristles that come to a point in order to scrub the grout lines only after giving the chemical time to work. Finally, Rich uses a mop designed for tile and grout which is made from a t-shirt like material. He uses the mope to absorb the dirt from the tile surface moving it in a figure-eight pattern.