I recently cooked a pork roast in my crock pot using BBQ sauce. Well, I must have let it cook too long because the bbq sauce is now part of the bottom of the crock pot. I don't know how to get it to come clean. I have soaked it for days, I have chipped at it with a butter knife, I have boiled it, nothing is removing it. Do any of you have a suggesting for removing the baked on bbq sauce?