Don't put the pan in the dishwasher if it has burnt-on food.
If you have burnt food hopelessly affixed to the bottom of your aluminum pot, don't start prodding the mess with a metal spoon or spatula, as you will scratch your pan's surface. Instead, shake as much of the mess from the pan as possible, and then try pulling out the excess using your hand. After that, begin removing the rest of the burnt food.
Fill the pan with cold water.
Add about 1/4 cup of white distilled vinegar to the pan.
Put the pan on the stove and bring to a low boil. Turn the temperature to the lowest degree possible while still maintaining a low boil. Boil for 10 minutes.
Remove from heat and allow the pan to cool to warm. Wash the pan using a sponge and dish soap. The burnt debris should easily wash way.