I visited my son over xmas and found that they had left all 4 cast iron pans out in the weather, for months.... 3 were rusty, like 100% coverage of orange, one musta been used to fry bacon before being left out uncleaned, so much grease it couldn't rust, but it collected a pound of dust and dirt.... that one was easy, boiling water and paper towel repeat, again and again.... the others each required an hour of the various stainless steel wire brush wheels (set from harbor freight $8) on the hand held drill. Got all the rust and old seasoning off and reseasoned them (wipe with oil and bake), they are as good as new, maybe better.
