When I bought my current boat, she was used as a liveaboard. PO was quite unclean and smoked cigars. The smell was terrible.
I removed all internal wall covering battens and washed the hull from inside - and that got rid of most of the smell (but what bear of a job that was, never again, I had to take apart the *entire* boat).
The cushions still smelled for a while, but after being stored for a winter in a location where they were reasonably aired - the smell is no longer there.
So - it can be removed, but it may not be easy.