I use ONLY cast iron. As Gnu says, only have to clean it right after using with stainless steel, or even only one of those green scrubbies. As they say, NO soap as it takes out the oil. Have never had to soak it. The other night Rob came home and found I had left a burner on under it. It was VERY hot. No harm done at all. I use it daily at least once, quick rinse and ready for the next go. Same with large covered, cast iron pot, good for soup or stew.
"Cure it" - put on burner, put in enough oil to cover lightly, turn on burner and warm the pan. Should not smoke! But mine did the other night and no harm!