Rub Some Soap on your Cookware
Cooking with a campfire will have your pots and pan coated in burnt bits and stains, and washing them is a chore. The sponge, even your fingers, will get stained. The worst part is that your pots and pans might have stains stuck to them regardless of how hard you scrub.
Just lather up some soap and rub it all over the back of your pot before you cook. This creates a barrier between your pot and the campfire. So, as soon as you scrub with some water and more soap, the stain comes off immediately.