SS dishwasher bodies with insulation

I get those from time to time. I can't bring myself to turn them in as "dirty" so I get the tar gunk off. The easiest way I've found is to use a propane torch to heat up the tar gunk and scrape it with a putty knife. Keep in mind, I'm not setting the stuff on fire or burning it, just applying some heat so the gunk will soften and it will scrape off pretty easy. The next one I get, I'm going to try a heat gun and see if that works better.