Hello! I know exactly what you mean because my dad’s favorite reading chair had the same issue. Regular fabric fresheners only mask the scent for an hour because the odor is trapped deep inside the cushion foam. We finally booked a deep sanitize with Chicago Couch Cleaning
https://chicago-couchcleaning.com/ and it worked wonders. Their deep steam extraction actually pulls the oils and bacteria out of the padding instead of just covering them up. If you are looking for professional upholstery cleaning services in Chicago that can handle deep organic odors, they are fantastic. The chair smells completely neutral now and feels fresh again. It completely saved the furniture from the trash!