I’ve never done felt before but in general a couple of days in the sun will remove a lot of odors.
If you want to go higher tech there are ozone-based odor removal solutions.
ELINP Industrial Ozone Generator 10,000 mg/h High Capacity Commercial Ozone Machine Ionizer Air Purifier Deodorizer Ozonator for Rooms, Smoke, Cars and Pets https://www.amazon.com/dp/B07WR2P9NK/ref=cm_sw_r_cp_api_glt_fabc_R6APNJFBGRGDKSG0CH0P
Is washing it out of the question?
Maybe @phoenix is still around and has pointers?