So I now have a clay baking dish, I found it over at my grandfather's buried in a shelf, has probably been there over 10 years. It has been protected, so is in brand new shape. How do I cure it? It is just baked clay and I know it needs seasoned, but what is the best way? I am guessing wipe it with vegetable oil and bake it...but I would rather know for sure than just guess.