I need some advice. I attempted to clean a kitchen and food prep area along with 2 restrooms in a bowling alley. I used my challenger with Tile and Grout brush. I presprayed a Tile and Grout cleaning product purchased at a local hardware store. (1st mistake) Vac'd/swept entire tile area. Presprayed, let dwell about 20-30 minutes then cleaned the area. The tiles came out OK but the grout (white) lines looked as bad as before and the dirt/stains did nt budge. Owner says no sealer was ever applied due to slip hazard. Could I have done anything different. Thanks

Did you perform a test: Strip &/or Clean to help determine what (and how much) is going to be needed? You're also correct about purchasing from the hardware store,even though some might beg to differ.I'm a DIE-HARD Stonetech guy, but lately I've been field testing Harvard's Alkiline/Acid products with great results.I firmly believe in how you aplly your product and how much dwell time is given plays a big role in the out come.With the OP,you're using a bigger chunk of the cleaning pie,agitation.I don't know how fast you're moving but I'm told that with OP tile cleaning,you get better results when moving a little slower.Email if you'd like to.
Patrick

Sometimes. when you want to see what is really achieveable with soiled grout, take a small sample area - maybe just a single line - and go to work on it be hand. Spray on your cleaner, let it dwell, then scrub it with a small brush that fits your hand.
You'll probably get a pretty good idea this way how light the grout can be made to look. Maybe try some bleach on it as well. What was thew original color or shade of the grout. Not all grout was white, or a light color. It's unlikely that grout than has been seriously soiled, and been so for some time, will come all the way back. Also, check to see what the guys at the dirtygrout.com board have for suggestions.

hiyas Chuck

other than the above, i wonder if your dwell time of 30 minutes was too long. you want to make sure the prespray doesn't dry.

thanx --- Derek.

Moving side to side slowly with your machine in the center of the tile and your brushes to the grout makes for cleaning faster and better.

Don't use store bought products as you will not get the results your customers are looking for.

Steamway makes several grout and tile cleaners, the Blue one is what you want for restrooms. Turbo blue is its name.

Just a thought ! What about an actual high temp steamer? That may work. Any feedback?

I use a deLonghi steam vapor machine. At about 300
degrees Fahrenheit & 60 psi, it really blasts out the
soil. That doesn't mean, however, that you will always be able to restore the original light-colored
or white grout to its original appearance. Sometimes you can remove a lot of soil and get back 80 to 90%
of the original appearance, but not more. I always
advise the customer of this so that he/she will be
realistic. A steam vapor machine is best used on smaller jobs, or just the tough parts of larger jobs.
It's a hand tool, and would be painful, and SLOW, to try an do an entire large floor this way.