More in Kitchen
Use bleach and soap to remove any grease or oil on the existing grout surface. An old toothbrush is the perfect tool for getting into the grout.
Once the grout is clean and dry, paint the grout stain onto the grout lines with a thin paintbrush. Try to stay within the grout lines. Allow the stain to stand for 20 minutes.
After 20-minutes, use a sponge to wet the tiles. Allow the water to stand on the tiles for about 5 minutes.
Use a scrub pad and remove the stain on the tile, concentrating on the grout lines (where you want the stain to stay).
Go over the tiles with a towel and clean up grout lines.