Recently we had a small oven fire (gas oven) and used the fire extinguisher to put it out. We have cleaned the oven multiple times to get the powder up. First with soap and water then with oven cleaner. However, even after using the oven a couple of times since then, when it pre-heats, it smells like the fire extinguisher powder. We even took the bottom panel out to clean underneath. Anyone have any suggestions? Are there professional oven cleaners out there who will make the oven like new?