Apply denatured alcohol or wood soap to all chair surfaces according to manufacturer's directions, including underneath arm rests and seats. This will kill any mold spores causing odor.
Place the chair in a sunny, dry spot for a week. The sun's rays will dry any moisture trapped in the wood.
Sand the chair and then refinish it with two to three coats of wood stain or paint to eliminate stubborn odors.
Leave the chair in a dry spot for 48 hours to dry completely.
Apply a clear coat to seal in odor and protect the finish. Allow it to dry completely before moving the chair.