To remove stains from granite, apply a poultice to the stained spots, use plastic wrap to cover the area, and peel off the tape and plastic wrap after 24 hours, according to How to Clean Stuff. Let the poultice dry for several hours or days, and get rid of the paste using a plastic scraper.
Before starting the stain-removal process, determine whether the spots on the granite countertop are stained or damaged areas, advises How to Clean Stuff. Stains typically look discolored due to staining agents and disappear once the staining agent is cleaned. In contrast, damaged spots result from damage or corrosion by acids, and they cannot be removed.
Next, find out the cause of the stain to choose the right poultice combinations for removing it, notes How to Clean Stuff. Organic stains caused by coffee, soda, tea or mustard can be removed using 30 to 40 percent hydrogen peroxide. For inorganic stains caused by ink, dye or dirt, use hydrogen peroxide and rubbing alcohol. Pure acetone may remove oil stains, whereas bleach can possibly clean biological stains caused by mold or mildew. A white powder called iron-out is likely effective to remove metal stains.
After applying the poultice, allowing it to dry and removing the paste, use a piece of cloth to wipe the remaining paste, instructs How to Clean Stuff. Then, clean the area, wipe with another cloth and repeat the process to remove stubborn stains.