The Kitchn offers a nifty trick for cleaning burnt enamel pots and pans, and it doesn’t require hours of scrubbing. All you need is baking soda and water.
Let the water come to a boil, add the baking soda, and give everything a good stir. After a few minutes of simmering, use a wooden spoon (no metal on that enamel surface, please!) to nudge off the burned-on bits. Just like that, all that yucky stuff will release from the pot, minimal elbow grease required.