I've been working on backward pumps and getting more comfortable with backward skating in general (I'm a newbie). I usually wear black boot covers while practicing since wanted to keep the "new" look of my skates. Last practice, after knocking the inside part of my boots together repeatedly from doing these backward pumps and backward 1-foot glides (the coach told me that the free leg should return right next to the skating leg after the initial 'pump', but of course, I lacked the motor control for that...) I noticed that these grey/black-ish smudges have developed on the "inside" part of the skates. I've noticed previously that my laces were getting dingier and dingier, especially since after I started practicing with the boot covers, so I immediately thought there's a possible correlation. I've also noticed other "smudgy" parts like this, particularly on the region where the boots are supposed to crease, but it seems to have spread somehow
Whatever it is seems to have transferred from the laces as well to the tongue of the boot!
The boot covers are lycra, I think, and I just purchased them from the pro-shop where I take my lessons, so they're mass-manufactured and nothing special, or so I thought. I also wondered whether it could be due to some transfer from something else in my skating bag, but I only keep the skates in the main compartment and everything else in the pockets. I do have to walk quite a bit from the rink to my bus stop so perhaps that walk + the tight confines of the bag did something to the boot somehow ... I'm at a loss as to where these smudges came from. They do not look anything like scuff marks you would get if you scraped the skates or something. I tried first wiping the area gently with a damp towel wet with soapy water, which did not work, but I didn't try any more aggressive methods after that since I don't know how to deal with leather and I don't want to damage the boots any more than I already have.
Has this ever happened to any of you before? Any suggestions about how to clean it?