I have my doubts that anyone else would have this problem. My husband put a cap at the bottom of our chimney liner to improve the draft. Below is the furnace on the same flue, supposedly illegal in NY. So to check the cleanness of the liner and also the operation of the oil furnace, he attempted to remove the cap. It was stuck with creosote and wouldn't come off, not to mention there isn't a whole lot of room to manuever in between the chimney and the liner. He tried every brute strength way to get it off, from dropping a monsterous steel bar from the top to pound it off, to drilling holes and trying to rip it off using a long screw attatchesd to a bunch of other junk that provided leverage. No luck. I had found some book excerpt on amazon that described the chemical properties of creosote. It said ammonia dissolves creosote. I forgot to mention the book read like it was from the 1800's. So I told this to hubby, but was dismissed for about a week and a half. Then he was desperate and finally agreed. I sent him out with an old saline flush syringe(no needle on it) and a cup of ammonia. He also needed a top of a sock rolled like a sweat band above his wrist in case it ran down on his delicate arm. He said it did nothing of the sort, just went right in the seam. A day later he was back out there to see if it did anything, low and behold it basically just came right off with a little prodding with some chisel thing ducktaped to a metal bracket thing. He came in saying how he couldn't believe how easy it came off, and of course that I was right all along.