Is that the same type of thing as Goo Be Gone? Tried that.
I got it off finally by using a combination of advice given in this thread and another one.
1. Goo Be Gone, Tar/Bug Remover, Fingernail polish remover worked on some of it but not all of it.
2. Then I tried the 0000 steel wool. That worked on some, but was going to take more elbow grease than I have and was very, very slow in removing the gunk.
3. Then I picked up the plastic lid to the fingernail polish remover and used it to scrape. And actually, that worked better than anything I had used up to that point. But the majority of the mess and the thickest part of the mess wasn't being affected at all.
So, I came back in and did another search and found another thread where someone recommended something else and THAT WORKED!!!
4. I started up the bike to let the pipes just get warm and as they were warming I saw part of the goo start to lift, so I let it warm a bit more and then took liquid soap detergent on that fine steel wool and VOILA! it came right off. All of it.
I used so many different things, I don't know if everything else I used before this had loosened it, or if it would have come off that easily if I had only done step 4. But it is off the header now. So I'm waiting for it to cool completely before i put some polish on them to see what kind of difference that will make. Actually, they look like they are back to normal right now, but I just think that while I'm working on them I'll go ahead and try the metal polish and see what happens. The very, very fine steel wool and the plastic lid used to scrape did not leave any visible marks at all. So I think I've successfully removed the goopy mess without damaging anything. And the nice blue color is still there!
