otherwise soak it in hot water with washing powder/soda crystals for about 15 mins and give it a scrub with a scourer/brillo on the outside, wash the iside with something not as scratchy on the inside and make sure you give it a good rinse after.
Only this week I burnt a stainless steel pot and cleaned it with bicarbonate of soda - just added one heaped teaspoon (was a small pot) to virtually boiled water and cleaned it. Five minutes it was shining and no sign that it was burnt.