I was talking to a guy that puts a soda can size of ammonia in his air intake box to keep down the accumulation of creosote in the firebox during the off or idle cycle in his OWB. He said that it was from a tip from an "old timer" and that they used to do that in their old wood furnaces. Ever heard of this? I did a search here and only came up with glass cleaning threads. I thought that ammonia was quite corrosive to steel itself.