When you have baked on or cooked on grime you are fighting with on your pots and pans and bakeware, try this:
By Carly from Lynnwood, WA
After making applesauce I found I had burned apple on the bottom of the pot. Lots of it. Never should have answered that phone! I put baking soda directly on the burned apple and added a little water. I then reheated it to boiling and the apple peeled off. You have to watch the pot so you don't burn the stuff again, but this works to get heavily burned pots to the point where you can then use the baking soda and vinegar.
When you mix baking soda and vinegar, they bubble vigorously and create carbon dioxide (the bubbles) and salt water. Is it the bubbling action that does something? If it is salt water that helps, why not just add the salt to boiling water? If baking soda and boiling water work by themselves, why add the vinegar? I am always puzzled by the use of this combo.