I recently discovered the wonders of hydrogen peroxide when its mixed with baking soda (USA / Canada). It’s amazing. Someday I will write an entire entry detailing the many, many things you can do with this simple mixture. It saved a cream coloured shirt that had been smeared with grape jello on New Year’s Eve six months after the fact. Today I’m saving tile grout.
Let it sit for half an hour or so, and then re-scrub the paste into the grout before rinsing the surface clean.
Et voila. Clean and lovely.