I find anything you'd use a wet Magic Eraser on, I get a better result with Mentadent toothpaste! Think about what's in it: Peroxide, baking soda, and a fine abrasive. My husband used it to clean the really stubborn stuff off the top of our white stove-top, and it worked great!
We recently had a white tile floor with white grout installed in our bathroom. How stupid are we! I have been searching for something to clean the grout, since it was dirty from pretty much the second week. I have found that soft scrub with bleach and a grout brush work well, but it is a PITA to do. I am really interested in this Finazzle stuff, since it seems like a much easier process than the soft scrub.
We use a mixture of bleach and baking soda- make a paste (runny), and apply to grout. I use a ketchup bottle to apply. Leave it on for a couple of minutes, and then wipe it off with a damp sponge. Works magic and is good for large areas.
I did this and WOW what a difference!
I actaully had a marble company come in to refinish my floor tiles and they were so impressed at how well it worked, they finished the job for me using this process at no extra charge.
I just got the Finazzle from Ace. I spent $700 getting a grout cleaning company to do my kitchen and hallways. What a rip. You could hardly tell the differance. The Finazzle made my grout NEW instantly!! I saw that they even make a grout cleaner that's safe for marble tiles.