Grout-eez cannot be used on natural stone it can etch the stone (made for ceramic and porcelain tile & grout).
Wait 24 hours after you are done cleaning your grout to get the true color and results.
Let Grout-eez dwell on the grout for at least 5 to 10 minutes.
You need a good stiff bristle brush to scrub grout (do not use something like a tooth brush).
Mop the area as soon as you are done (clean 10 sq. ft. at a time so it doesn't dry & get sticky).
Grout may not be as easy to clean as we show in videos.
A single bottle of Grout-eez covers approx. 250 sq ft. To figure out the square footage of a room you multiple length x width.