rwhite
Minister of Fire
How are the cleanouts positioned in relation to the fireplace? I'm just thinking of you sealed the doors and opened the clean outs if they are vented into the fire place you would have an idea of your plan will even work. I'm sure it would chew through the wood as the air would be routed to the bottom of the fire. One other thing I would have concern is if the structure, lintel, and damper can handle that level of heat. The inside of a fireplace burning with the doors open is nowhere near the heat level you may produce.