Mix warm water with baking soda to form a paste
Apply the paste directly to the grout lines
Let it sit for 5 to 10 minutes
Scrub the grout with a stiff-bristled brush or old toothbrush
Rinse the area with warm water
Spray white vinegar on stubborn spots if needed
Scrub again and rinse thoroughly
Use hydrogen peroxide for deep stains if necessary
Wipe the grout dry with a clean cloth
Repeat regularly to prevent buildup
Seal the grout after cleaning if it is unsealed