Article: Soaps and detergents are great at cleaning most cookery, but they should be avoided when it comes to cast iron pots and pans. The sulfides in most detergents bind to the oils in the skillet and strip them, leaving your skillet as naked and vulnerable as it was on the first day of its life. It still can be re-seasoned, but it ends up being more work than necessary. Different process, but same reasons. This process can eat through the non-stick coating you've created and promote rust. While steel wool is effective at removing food and other buildup, it cuts right through the seasoning and forces you to start at square one again. Far better to stick to the potato method for cleaning (no pun intended).

What is a summary?
Avoid using soaps and detergents. Never put the skillet in the dishwasher. Try to avoid using steel wool to clean your cast iron cookery unless in dire need of cleaning.