Removing dried or sticky toothpaste stuck to the wall may seem straightforward, but it can damage the wall depending on how dry it is and the material the wall is made of. Dried toothpaste becomes hard and almost cement-like. Tile walls can usually withstand the scrubbing and scraping necessary for removal, but this can damage a painted wall. Using care and the right cleaning materials allows you to remove toothpaste successfully from any wall surface.
Scrape as much toothpaste residue from the wall as possible, using a plastic knife or scraper. Avoid scraping into the paint or pulling up the paint when removing dried toothpaste; it's best to only scrape gummy, partially dried toothpaste from a painted wall surface.
Combine a squirt of mild liquid dish detergent with 1 quart of warm water. Soak a rag in the cleaning solution.
Place the rag over the toothpaste spot. Hold it in place for two to three minutes so the warm water and detergents can loosen the paste.
Rub the toothpaste with the rag, re-wetting as necessary. Scrub painted walls gently until the toothpaste is completely removed from the wall. Tile walls can withstand more vigorous scrubbing.
Inspect a painted wall for any remaining stain after it dries from the initial cleaning. If a stain remains from the toothpaste, mix 1 tablespoon of ammonia with 2 quarts of warm water. Wash the spot with the ammonia solution to remove the remaining stain.