I bought a Fender SS Deluxe 90 that smelled like it had been in a swamp or a flooded basement for 20 years. I presumed the smell would fade in a couple of days, but I was very wrong. What worked were (bamboo?) charcoal bags and leaving them in the cab. After a day or two, they need to be put in sunlight for a couple of hours, which I did, and the smell disappeared completely and pretty quickly. They are currently doing excellent work on the couch that the dog vommed onto after eating a pack of butter - trust me on this, rancid dog-vom butter is not how you want your home to smell.
These are (I think) the exact ones I got, but there's loads on ebay etc.
https://www.diy.com/departments/4-x-20 ... KUEALw_wcB