To clean your painted walls, Carl Minchew, director of Product Development at Benjamin Moore, suggests starting with a clean cloth or sponge and water. If that doesn’t work, dip the rag or sponge into water mixed with a little dishwashing liquid, the milder the better.
If the stain persists, apply a few drops of soap directly onto the wet sponge or cloth you’re using. For more stubborn cases, you could apply a little soap right onto the stain.
If you need to resort to a stronger product like Fantastik or Formula 409, realize they have strong solvents in them and can soften the paint surface. Make sure that whatever you do to get rid of the stain, you rinse the wall afterward with plain water.