This video shows a common tradition for cleaning tile floor grout. Vinegar and baking soda mixed into a paste will clean rout pretty well. Not sure about the bleach pen for colored grout. BUT- Do you have the patience to actually clean your floor with a toothbrush? And what about the tiles themselves? They can get pretty filthy and are difficult to clean successfully. See how we clean floor tile & grout professionally at cleancareboulder.com.