I love the look of tile, but I hate the upkeep and maintenance that comes with keeping the tile grout looking nice and clean!
Shortly after we bought our house new, my husband sealed much of the tile grout, which has reduced the maintenance (for now!), but there are still occasional spots that pop up in the grout - both in the floor and the shower.
Rather than just spray a cleaner full of chemicals on the spots, I decided to try a natural solution first.
So, I used a small bowl to mix up part baking soda and hydrogen peroxide to form a paste. Then, I used an old toothbrush (or you could use a wire brush for bigger jobs) to spread the mixture on the dirty grout spots and I scrubbed the spot for a minute or so. I let it sit on the grout for about 10 minutes and then I rinsed it with water and let it dry.
It will be difficult to tell right away if you were actually successful in cleaning the spot, since grout darkens when it's wet. But, once it dried, both of my spots were gone.
Hydrogen peroxide does act as a bleach, so you might want to test the solution in an inconspicuous spot before you do the entire job. I used it on my brown tile, and it was fine.
Additional Grout Cleaning Solutions (that I did not try):
I've also seen some recipes that include vinegar and lemon, but I read that vinegar and lemon are both acidic and might not be good for the tile grout.