Far as I can tell, someone wrote:
>Baloney. Deeply pitted cast iron ware can, indeed, be ruined. Cast
>iron cookware that has had petroleum distillates in it is ruined. Cast
>iron heated and rapidly cooled can warp or even crack, and either of
>these mean it's ruined.

Years ago, I found a skillet in a garage that must have been there for
at least a few decades. Rust, bugs, you name it.

I scoured it with 40 grit, then 80 grit cloth, then finally 280, then
steel wool (4 ought). Then I washed it a few times and then re-seasoned
it.

Still using it today.

If it isn't warped or cracked, it's still good. Bar nothing!