I'm sure this is addressed elsewhere, but the search function isn't adequate to the task.
I have a Lodge skillet, bought new c. 20 years ago, and there is a buildup mostly on the interior sides of material that I think is carbonized food. Scaly black stuff, some adhering to the sides, and some that flakes off into the pan when cooking.
I suspect this may be due to using oil at high heat to soften batches of tortillas. But I don't know. (A second CI skillet, bought at the same time, never developed this problem, but was not used for this purpose.) Come to think of it, there's a similar crusty buildup near the edges of my carbon-steel wok.
Any ideas on how to remove it? Will re-season if necessary.
Thank you; any advice appreciated.