Interesting comment from Wilfried which reminds me of the traditional method of treating frying pans before the advent of ptfe coatings. Wipe round with oil and then put on the stove till it baked on. Do it another couple of times and you had a hard black surface. You can now fry perfectly well, but when finished, just wipe out rather than wash.
For a short period in my life I had an isolated cottage that had not changed from the mid 1800’s, ie, no electricity, running water or sanitation. Cooking on an ancient range with old iron pans.
Kind Regards Roger