I found a rusty but not pitted vintage Wagner ten inch skillet in like 2002.
I hit it with caustic oven cleaner in a cardboard box in my garage, left overnight, rinsed it and repeated.
Ran it through the dishwasher and then scrubbed it with soapless steel wool; wiped it with paper towels and set it on a hot stove to flash to dry.
Then a super thin coating of organic (important) flax seed oil, put it upside down in the center of a cold oven, set to 500ƒ and held it there for an hour.
Let the oven go cold, repeat the oil coat-500ƒ thing 4 more times.
Rock-hard and impregnable, black as can be, clean gently with warm water and a natural fiber brush, sometimes kosher salt. Once every month or two I hit it with some more flax seed oil and heat it on the stove just until just before it smokes.
It's a great pan, but I did have to learn how to use it.
MUST refrigerate that flax seed oil or it will go bad. Really stinky bad.