How to remove black from floor joints

Hydrogen peroxide

A product that is part of the first aid kit, but is also very useful for cleaning, disinfecting and whitening the joints.

Pour baking soda into the floor grout lines.
Add hydrogen peroxide and liquid dish soap.

Leave it on for 5 minutes, then scrub well with a toothbrush and rinse.

White vinegar
Advertisement:

White vinegar can be used in multiple ways. In addition to cleaning joints well, it is effective against lime and mold.

Pour vinegar on the joints.
Add a little baking soda.
Scrub vigorously with a toothbrush and then rinse.