Well it didn't wipe off the first two tries. I was trying to be really gentle. Since you guys said it wasn't likely scale rot, I was less scared of messing with it, so I got some soap and water and really tried to scrub it off. I thought she'd get angry at me for the first time, but she remained very calm and just curled around my hands. After a few minutes I was able to get it off! It kind of came off in a couple pieces, like a scab or something... But once it was off, the scales looked good as new. She still looks good today, so I don't think I hurt her.