Hi Alan, I hope this helps! https://brendid.com/ultimate-guide-to-cleaning-grout-and-tile/
I've had a good luck with a paste made of vinegar and hydrogen peroxide left to sit on it for 24 hours. You might also consider re-sealing your grout, a couple of coats of a good grout sealer could to wonders in help you keep it clean in the future.
I used a paste of Oxy Clean and used an old toothbrush to scrub. Came out really clean. Then sealed it well
And here are some Hometalk projects on cleaning grout.
Once it's clean make sure to reseal it to cut down on how often you need to clean it.
If it is really bad, you can use Lysol Lime & Rust Remover Toilet Bowl cleaner, comes in a black squirt bottle. Scrub with Scrub Daddy or Mr. Clean Magic Eraser. If stubborn, use a scouring stick to scrub. make sure to seal once you have it clean. You can also paint it if you feel it's beyond help.
clean it with this https://amzn.to/2Xx0FNc
and seal it with this https://amzn.to/36yNYpi
I use Young Living's Thieves cleaner
Hi Alan - This is the shower cleaner that we use to help keep grout and tiles clean and minimize the mildew - it works on kitchen grout too. I've also included a great article about mold if it's gone that far. Hope this helps! Hugs, Holly
PS - We have a FREE eBook with recipes for all of my homemade and all-natural cleaners. You can download it here --> https://pinkfortitude.com/thank#GreenClean
Hi Alan, here's a quick video to help you out,