When I first got my Spirit 500 I would cook salmon fillets on it --- flesh side down first and then finish on the skin side - it would always stick to the grates so I would just scrape the meat right off..... Of course on the next cook I would crank it up to 600+ and burn the skin and then just scrape it down into the box...... Yeah, I was stoopid back then ---- but I never let it build up to the levels I've seen in 'freebies'.