Baking Soda

Baking soda is the cleaning tool that I use for both of my cast iron skillets, when some food residue has gotten stuck. After the skillets are cool enough, I simply boil some water in them with some baking soda for a few minutes and them stir and scrub carefully. Because the baking soda is a natural ingredient, I tend to use more than I need. After cleaning, I rinse the skillets clean with hot water and use towels to dry them. The next step is putting the skillets on the stove with medium heat to remove extra moisture and apply a thin layer of oil to prevent rusting.
As my extra precaution, when I bake pizzas with my 12" skillet, I apply a thin layer of cooking oil outside of the skillet, including the handles. I put it into the oven while the oven heats up to the desired temperature. Then I simply bake the pizzas as usual. This method is like 2 birds with 1 stone. You do not have to spend extra time just for reseasoning or worry about spotty rusts.