I work at a costume and tuxedo rental shop, and my manager let me take one of the damaged wig heads home to have fun with. Since we had recently made a Joker wig (a la Caesar Romero), and since the new movie was out, I decided to try and make it up like the new Joker. Getting the markers to smudge and blend was a bit tricky, but my clear blender did the job.
Besides, I had fun.
Prismacolor markers on a foam wig head.