How to remove black from floor joints

Sodium bicarbonate

When combined with water, it is one of the most effective cleaning products on various types of surfaces.

In a bowl, pour the water and baking soda and mix until creamy.
Use a toothbrush to apply the paste to the grout and let it sit for 5 minutes.
Scrub the brush between the joints to remove dirt and then rinse.

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 over the floor joints.
Add hydrogen peroxide and liquid dish soap.
Leave it on for 5 minutes, then scrub well with a toothbrush and rinse.

White vinegar

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

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