I'm going to try thatI leave an open jug of ammonia in my chimney cellar clean-out over the summer and fall, just let it evaporate. From what I've read, the vapor helps loosen creosote from the flue to keep it clean. My chimney guy said whatever I was doing, keep it up because it was clean when I had it inspected last year. Been using this for years for my wood furnace flue - burn 6 cord/year for the last 10 years and I clean it every year. Seems to work.