My nephew visited for a weekend and left a mural on the hallway wall. A green sun, a purple dog, and something that might have been a dinosaur or might have been a potato.

Crayon on walls is one of those parenting moments nobody warns you about. The wax bonds to paint surprisingly well. Water and soap do nothing.

Method 1: Hair Dryer

Crayon is wax. Wax melts. Point a hair dryer at the crayon marks on medium heat for about 10 seconds. When the crayon looks shiny — that is the wax melting — wipe it off with a dry paper towel. The wax transfers to the paper towel, not the wall. This is the gentlest method. No chemicals, no scrubbing.

Method 2: WD-40

Spray WD-40 onto a paper towel, not directly onto the wall. Wipe the crayon marks. Then clean the residue with warm soapy water. Test on an inconspicuous spot first — WD-40 can affect matte paint finishes.

Method 3: Mayonnaise

This sounds fake but works. Mayonnaise is oil and egg — the oil dissolves wax, the egg proteins help lift it. Put a dab on the crayon mark, let it sit 5 minutes, wipe off.

The mural came off in about 20 minutes with the hair dryer. No paint damage. My nephew was slightly disappointed that his artwork was temporary.