Baking soda can remove crayon from walls and even from launderable items.
Place one cup baking soda in the wash and run as usual.
(Note: If the crayon doesn’t come out of the fabric, wash it again before placing it in the drier, otherwise, the heat could set the wax and color in for good.)
To remove crayons from walls, make a paste and scrub. Rinse with clean water.