I use peroxy at 10 oz per gallon just like I would for carpet. I also carry along a wet vac a swiveling grout brush and a bunch of double cotton pads or some beat up tuways that I wont use on carpets. I usel the tile and grout brush on the Challenger. When I first got it I thought it was cheesy but it does a good job.My only complaint is that the bristles are too short for deep grout lines. That is where the other brush comes in.