Our son decided to draw on his window in the back of the van with a crayon. I tried various cleaning supplies to get the crayon off. None of them worked. Later on, I was trying to fix some of the squeaky doors around the house, and then I noticed that the WD-40 can states the WD-40 can be used to clean off crayon.
The WD-40 easily to rid of the crayon, but it left a cloudy residue. With a little Windex, the window came clean.