Cleaning The Ducts

Just make sure you consult a professional or someone who deals with smoke damage repair enough to make the proper decisions in this case and so you don't cause more harm than good. Consulted professional restorers and the smoke removal methods they will use, or you might try to use yourself. A chemical sealer might be your best bet to simply seal of those odors. They can secure the smoke permanately to the sides in the duct, because with ducts having so many spots to clean, in the crevices and what-not, that might be your best bet.