Add some water to the pan and then two cups of vinegar. Set it on the stove and bring to a boil, then remove it from the heat. Next, sprinkle two tablespoons of baking soda and allow the mixture to soak for several minutes. After pouring everything out, lightly scrub the pan and rinse.
As for those pesky scratches, the secret to banishing them? Shoe polish. Simply rub it into the affected spots with a cloth and rub away the excess. (Also, be sure to use the right color for your couch!)