It will eventually wear off.

However, I teacher I worked for had wipes that removed permanent marker. They were great when a student accidentally wrote with permanent marker on the reuseable math board. Eek!

Maybe try searching google for them.

Oh, and Shout! (stain remover) got everything off my brother and I when we were little.

Lava soap or other industrial type soaps for mechanics and such might work too.

Good luck!