I ran into a fellow today that says he uses a large bowl of ammonia to clean his chimney when the wood stove has gone cold . He says he sits the bowl of ammonia in the bottom of his chimney ( through the clean out ) & leaves it there for a couple of days . He claims that when he removes the bowl , that the chimney is clean as can be & that all of the accumulated creosote falls to the bottom of the clean out . He says he has a 12" x 12" tile flu . Just wondering ...............