I just went through this 2 days in a row. I melted my ski pants to my pipes. The first time, I sprayed Plexus windshield cleaner on it, and then scraped it all off with my thumbnail. It took a while.
The next day, as careful as I was, I did it again. This time, I sprayed over cleaner on the hot pipes as soon as I pulled into the garage. I let it sit until the next day. I was amazed that most of it came off with my thumbnail in chunks in a minute or 2. I then sprayed on the Plexus, let it sit for a minute, wiped it off, and used my thumbnail for the rest. I had it all gone within 5 minutes this time and did not leave a mark.
The first time, with just the Plexus, I ended up leaving some very fine scratches on the chrome surface that I could see only when I put a flashlight directly on the area. I haven't tried chrome polish yet, but hopefully it's something that will be gone after polishing. I'm still having a hard time believing that my thumbnails could put any permanent marks in chrome, although not noticeable.
Oh yeah, don't forget to clean the oven cleaner off with a wet towel before proceeding, and make sure you have a towel behind the pipe to make sure the oven cleaner doesn't get on any other surfaces.