works great
we have a glass fireplace door. It had black soot on it so thick I didn't think it would come off. I had sued the soot/water on a paper towel tricked.  That worked for the lighter buildup areas. But for the really thick stuff this worked great and I think it made it easier to clean the next time. We were told by the fireplace people that the black soot would burn off the door when it got a good hot fire going.  It didn't - only got worse and worse. So...searched and found the "trick" with the sot and water but the really hard thick layers only came out with this...and another one of the spray products made by this company works great too.
Rating: 5 stars