I use multiple cast iron pans everyday. My little side hobby is to find old nasty cast iron pans and rehab them. I have four pieces seasoning in the oven as I type.
I recommend cleaning your well-seasoned cast iron pans with hot water, your fingers and a nylon sponge. After cleaning, dry it off and heat it up on your stove top for about 30 seconds, then wipe it with a thin layer of your oil of choice (I use grape seed oil because it has a high smoke point). After it's totally cooled down, wipe it out again with a clean paper towel and get off any excess oil before you put it away. This will also help ensure that your pans are totally dry and won't rust during storage.
You do need to do this to the outside of the pan until it is well seasoned--that means shiny black--then you only need to do the inside of the pan.