I used to do leather work many, many years ago. I still have some old leather (Not as old as that frog though) in a tote that I remembered had been marked on with a marks-a-lot permanent marker. I found a piece that was marked on the back and tried the cotton ball and alcohol on it. Yeah, it made it worse. Some of it came off onto the cotton ball but mostly just spread out. Then I tried a magic eraser on another piece. Nope, did not work. A little ink transferred to the magic eraser but not enough to make any difference. The rough texture of the back of the leather holds the ink. I tried it on a piece that was marked on the front (smooth) side and after rubbing for a bit was able to remove some ink. More work than it`s worth for as little ink was removed. What made me think of the magic eraser was I have tan leather seats in my Caddie and the passenger seat got regular ink from a pen on it. The magic eraser got probably 95% of it off and what is left is hardly noticeable. Still irritating as hell though,
mnguy62 gave the best advice and that is what I would do. I am a minimalist with what I do to my collectables when it comes to trying to fix or clean something. I am like you with luck and would definitely mess it up other wise.
