Scrape off excess crayon gently with a plastic card
Apply a small amount of baking soda and water to a soft cloth
Rub the crayon marks lightly in circular motions
Use a damp microfiber cloth to wipe the area clean
Apply mild dish soap mixed with warm water if needed
Use a melamine sponge lightly on stubborn marks
Test any cleaner on a hidden spot first
Dry the wall with a clean towel
Repeat as needed until the marks are gone