I was telling a guy at work today how I burn regularely with the insert. A little back and forth later and he is telling me that, growing up, his Dad always kept a road flare next to their fireplace incase of a chimney fire. He said the flare would consume all of the oxygen in the chimney and minimise or put out the chimney fire. He said they never had to use it. I told him that I just burn seasoned wood and sweep once a year and that's the end of it. Either way it was an interesting idea. Wives tale of truth?