Burning out the cook chamber would fix the cook chamber, but I hate to think of where else that carcass dripped or oozed on while it was rotting.
Hmmm not sure I would want to cook on it but I would like to see the 3 year old carcass. Curious minds want to know.
While I personally would pass, there is a possibility someone could clean it and make it usable. Maybe a good power-wash o ar trip to he car wash might do it, but it is an electric smoker and would have to dry for days before plugging it in. Keep in mind that an electric smoker isn't constructed and sealed like a wood-burner.
For me, my biggest concern is that; even with a good cleaning, would it really be clean? Electric smokers like MES are noted for holding moisture in, many posts on the forums, our users say they have to open the door to get rid of some of the moisture when making jerky. So in the moist environment where did the bacteria spores settle that is not accessible to wash?
Now exposed to temperatures ranging between 40° - 140°, lack of oxygen, moisture, or high humidity can all trigger the growth of bacteria that could cause food poisoning. When smoking, the warm humid environment can bring spores back to life, the smoke and the heat will eliminate oxygen, making ideal conditions for bacterial growth. With heat, moisture, and lack of oxygen in these far away insulated crevices, will the spores bring the bacteria back to life? I would pass on the science experiment myself.