This video shows you how to clean grout using baking soda and peroxide. This solution will clean your grout, but it's the scrubbing action that actually does most of the dirt and grime removal. As a professional grout cleaner in Tampa FL I decided to simplify this technique. I started by ditching the baking soda and peroxide and use and oxygen bleach instead. The primary ingredients in an oxygen bleach are baking soda and hydrogen peroxide, go figure. The benefit of an oxygen bleach is that it is premixed and can be easily applied to a large area using a spray bottle. Then it can be left in place and allowed to dry without all the scrubbing. The instructions are below:
How to clean grout.
If spraying the oxygen bleach cleaning solution does not clean the grout you can use a floor scrubber on a pole handle to agitate the mixture into the grout between steps 3 and 4. There is no need to get on your hands and knees to do this particular cleaning. Grout cleaning is hard enough without using a toothbrush on your hands and knees.