Dirty grout in a bathroom can look a little gross. If you are selling or considering selling than tackling your dirty grout is a good idea. There is nothing like a clean bathroom to entice potential buyers.
I have tried many formulas to clean grout. A combination of baking soda and peroxide works really well. I like to mix the baking soda and peroxide to form a paste then I apply the paste onto the grout. With a small scrub brush or hard brush you can then clean your grout. It can be tedious but the end result can look amazing. It can make such a huge difference and make your tile look new again!