I have my grandmothers cast iron that is over 75 years old and still cooks great. I do as she always did (lived with her 13 years). After using I wash with hot water and Dawn. Then I place then on a warm burner to make sure dry. Only about every 3rd or 4th use do I use a very small amount of oilve oil rubbed into the pan to prevent rusting. As far as seasoning them I have never had to do that. She always claimed once seasoned properly they were seasoned. Just maintain them afterwards. I bought one of the new cast iron skillets - they are nothing like my old ones.