For those wondering how I did it:

First, I Boiled 10 quarts of water, added 2 tablespoons of vinegar, 1 teaspoon of sodium bicarbonate, two cups of coke and one half cup of lemon juice then stirred well . Waited 3 minutes, put the pan in the solution for 45 minutes, then added a quarter cup of chlorine bleach to the mixture. Then I scrubbed it with a firm toothbrush and put it back into the liquid for another 25 minutes. I took it out, rinsed it and it looked exactly the same, so I threw it away, then I went and bought a new one...