Suggestions for best grout cleaning and sealing for floor tile, 1/ 4 inch, sanded. (10 year old tile work)
Here's what I personally know.
Should have not used any kind of soap or cleaning solution that adheres to grout especially sanded.
If there's a buildup of crud/soap/cleaning stuff, then there's the old way. Stiff grout brush (industrial/professional) , no........not an old tooth brush.
White vinegar and water-make it as strong as you think necessary. Don't be cheap-vinegar is still cheaper than gas. Wet the grout good with your concoction, start scrubbing with that good grout brush. Rinse with clean water and use the best sealer you can get.
It will lift the dirt, not harm the grout and leave you with a clean looking, almost back to original condition.
Then and thereafter, mop with a vinegar water solution (milder-cup in 3-4 gallons of water).
If that don't work, there's stronger acids available at good tile suppliers, read the instructions, follow them closely, might work.
I did see Stanley Steamer offering grout cleaning finally. Maybe?
or find out their method-up till now it's been you, knee pads and a brush.
Isn't bad, smells like a salad.
A Great Place for Information, Comraderie, and a Sucker Punch.
Remodeling Contractor just outside the Glass City.
The easy way that works every time is to call your local carpet cleaning company and let them do it. For $200.00 bucks they will make it look like new.
Florida Licensed Building Contractor, 40 years experience in commercial remodeling, new homes, home remodeling and repairs and all types building maintenance.