I would process it. There will be a lot of plastic in it but there is also a motor, some wiring, and some brass and steel as well. I personally don't pass anything up if it's free and that close. But that's just me. The tub of dishwashers is usually made from plastic. If you are willing to let it sit around so the county can pick it up, why not just clean it yourself, that's what they'll do with it.