theredribbon:

Part water, part vinegar, and an optional part of lemon juice

Put the mixture into the pot or pan with a stain and let it sit on the stove for about 15 minutes before turning it on to a low heat. Let it warm up before taking the pot or pan off the heat. Scrub the bottom and voila… No longer stained. I’ve done this with several pieces of my cookware and the best part is that this is a natural cleaner.