My answer didn't take convenience into consideration because I didn't know that was one of the parameters.
Um, convenience is ALWAYS a parameter. Always.
Thanks very much for that Volrath video. Excellent. I think that pretty much answers my question. Now, that seasoning process is for carbon steel. Interesting that it's a lot easier to season a black iron frypan. You don't need any special oil or involved activity to do that.
Yes, Millions, Fe3O4 is magnetite, and it's a much more stable coating. The "rust converter" stuff makes that out of rust, which is Fe2O3. But rusty food? Ick.