Cast Iron pan seasoning Question

I have some old Wagners that were rusty when I bought them. Cleaned them up with some acid to remove the rust and then coated them with vegetable oil. I started cooking with them. After cooking, I allow them to cool and then wash with dish detergent and water. I cracked a Griswold by washing it when it was still really hot one day. Dry completely and coat with oil. I cook eggs in them and they stick less than the non-stick pans. Key is to keep them coated with oil and allow them and oil to get hot before adding food.