Try using white vinegar and baking soda. Sprinkle the baking soda all around and then squirt around some vinegar. Use just enough to cover the bbq sauce. Cover the top of the pot with foil and let it soak for a several hours possibly overnight. I do this all of the time and it works great for me even on my pots and pans. Usually after soaking, all I have to do is wipe it out with paper towels and then wash as usual. Hope it works for you. :)