Try stuffing it with crinkled newspaper. Change the paper frequently. The smell will absorb into the paper. (Also, when we had a flood in this area in 1976 - farmers suggested straw or hay in the cars to get the smell out of it.) Just a suggestion, haven't tried it, but a we had a musty smell in a small refrigerator freezer, stuck the paper crumbled all around, and when you take the paper out -- the musty smell is in the paper not the freezer. No chemicals. Just a thought.