Great results But Beware!
This product and the brush that was included did an amazing job of cleaning our 20+ year old grout.  It brought the color back to nearly new and a vast improvement over where we started.  Two notes of caution-We did not cover our stainless steel appliances in the kitchen.  When brushing the product there were some splashes and they permanently stained the appliances with little dots. I suggest either wrapping or covering your appliances or have someone wipe them down immediately after applying the product to your floor. Also, it was very difficult to remove the remaining product residual from the floor.  It foamed up and our sponge mop could not gather it all.  Finally I used a squeegy on a mop handle to gather the foamy residual into one place, sprayed it with 409 and that reduced the foaminess. We were able to cover more than 500 sf with one bottle and are more than pleased with the results.
Rating: 4 stars