I don't come across that problem very often, I tend to deal more with the exterior than the interior (95% of my clientele are collectors or garage queen enthusiasts). But here are a few tips to help eliminate odors,
Leave a few small trays of baking soda in the car while it's not in use, I would put one under each front seat and another in the back of the car.
Thoroughly clean the interior. Shampoo and scrub the carpets, clean all the leather, vinyl, plastic, wipe down the headliner and the upholstery with a damp cloth and cleaner.
Mist all the upholstery, carpets, and headliner with an odor eliminator like Fabreeze (I use a product by Chemical Guys called Odor Eater).
If you have one available to you, place an ozone generator inside the car and make sure all the windows and doors are sealed up tight.
Sorry for the late response, I don't check this thread often.