I do not know if this will clean grout. I wanted to tell you a much cheaper product. BORAXO. It is the same as the Oxiclean product you ask about. You get it in the laundry or cleaning section of your super market. Great for washing laundry to gets out stains. I use it everywhere No chemicals no rinsing

Try using Clorox Clean up. Works great, leave it on for a few minutes if the grout is stained or very dirty.

But if you do want to use oxiclean, just sprinkle it on the grout and mist with water to make a paste and let it sit fora while.
Boraxo is not a bleach, it's an alkaling borax powder plus soap.
Linda C

I assume Boraxo is the same as 20-Mule Team Borax? That's all I can find in my store. I have mildew in one place that nothing will touch: it's worth a try.