Zep for Cleaning Tile Grout

For years I put up with yellow grout in my bathroom. I scrubbed with everything imaginable to no avail. No more! I was recently in a local home improvement store and when I asked about this problem they suggested a product to me. It is totally amazing! No more scrubbing! The name of of it is Zep Mold Stain & Mildew Remover. Just spray it on, walk away for an hour or so and when you come back the grout is amazingly white again. This is a commercial product with bleach so make sure the area is vented well or leave the room while it works. Rinse it off and you are done. So easy! Sorry, not the best picss.