Permanent Marker on Rubber?

If its on the bottom, it will wear off. otherwise, permanent usually means permanent.

I agree. I have tried about 20 different "solutions" from various internet sites now, the stain being on the side of the shoe rather than the sole. While a few have dimmed the ink ever so slightly, the only thing that has helped a bit more has been using sandpaper. That smooths it out and makes it look different than the rougher surface of the sides, but helps. One thing I caution anyone to avoid is buying denatured alcohol. The smallest can in over $6 here, and it does nothing to help. I'm told if one can find rubbing alcohol like one has in the medicine chest, at over 90% active ingredient, that might help, but the most I can find is 70%. The sneakers are new from The Children's Place, but I only paid 99 cents at the thrift shop, and I've spent $10 trying to remove the price.