How to clean grout

https://www.hometalk.com/search/posts?filter=grout%20cleaning

use peroxide or medicinal alcohol and a small wire brush.

when you get it clean, talk to a tile shop on how to seal it.

I like barkeepers friend and a grout brush. If you still don't like the color once it's clean, you can always paint or stain the grout. After you get it how you want it, be sure to seal it to make it easier to keep clean.

This attachment is great for cleaning grout, https://www.youtube.com/watch?v=jXEDnFmLNnI

Scrub brush, elbow grease and a product designed for grout cleaning. Check out the grout aisle in Home Depot or Lowes. Bleach and some other cleaners erode the grout over time. Seal with grout cleaner when done. I tried a paste of Oxi-Clean with poor results.

Use a toothbrush with paste mixture of bleach and baking soda...let sit. Then rinse.

Cleaning Grout with Hydrogen Peroxide, Baking Soda, and Dish Soap

1. Make a paste.
2. Apply the paste with a toothbrush.
3. Let the mixture sit on the grout for 15 minutes.
4. Rinse the grout with warm or hot water to remove all of the solution.
5. Use a rag to wipe the grout to remove any leftover residue or dirt.

Mop the floor with clean water.

OR

Making a paste with OxyClean and water. Apply let sit for 20 mins. Scrub with toothbrush. Rinse well.

Once it's clean, SEAL!

This is how I do it: How to Clean Grout

1. Remove surface dirt with hot water and a towel.
2. Mix together ½ cup baking soda, ¼ cup hydrogen peroxide, 1 tsp dish soap.
3. Spoon cleaning agents onto grout and let sit for 5-10 minutes.
4. Scrub the grout lines with a brush. ...
5. Wipe clean.