Nothing works. Trust me.
What I've tried:
Alcohol 80% ( Diluted, then undiluted )
Degreaser ( Orange, Diluted then Undiluted )
Degreaser ( Purple Power, Diluted, the Undiluted )
Meguiars Leather Cleaner
Magic Eraser ( light only since abrasive )
Spray 9 is pretty similar to Purple Power. Can...