If you have a cast-iron pan with rust or caked-on gunk, toss it in the oven when you do a clean cycle, remove and season and it will be like new! This is the easiest way to clean your cast iron skillets. Just don’t use this method if you have a wooden handle, this method is for solid cast iron only.
I discovered this method by remembering my dad making a really hot fire in our backyard and putting the pans in that fire when they got really gunky. So I figured if that fire didn’t hurt the pans, neither would the self-clean cycle of my oven. It worked like a charm.
There are several methods to season your pan. I just wait for my clean cycle to end and for it to unlock, carefully pull the pan out and swirl some food-grade oil in it. When it cools, I use a paper towel to wipe out the excess.