How to Remove Black Stains from Floor Grout

a thick, creamy paste.
Apply the mixture directly to the grout lines using an old toothbrush or a small grout brush.
Allow it to sit for approximately 5 to 10 minutes.
Scrub the grout gently but thoroughly.
Wipe away the loosened dirt and rinse the area with clean water.

 

If the grout is particularly dirty, you may need to repeat the process rather than applying excessive pressure during the first cleaning.

 

Why Grout Becomes Dark

Grout is often more porous than the surrounding tile. Tiny pores and irregularities can trap