You can easily make a very effective grout cleaner from just two cheap ingredients. For this recipe you will need baking soda, hydrogen-peroxide, a small container and a toothbrush. In your container mix a half cup of baking soda and a quarter cup of hydrogen-peroxide. Mix them together until it turns into a runny paste. Now apply it to your grout with your toothbrush, leave it for about 10 minutes and then scrub it away.