As the owner of some 25 cast iron fry pans, I can testify how to clean cast iron. I have seen grandma's frying pan that was so thick with grease that you couldn't tell where it was made and it weighed probably a pound heavier, and all you do is you have to burn them. You can burn all the grease out, which will clean the pan, recoat with something to keep it from sticking and from then on it's a good pan till the grease cooks through it again. Cast iron is a good cook item, it's hard to find the nice light pans like Griswold made many years ago. There's a few out there but most of them like Lodge, are darn heavy and they're also too rough in the bottom. I have smoothed many of them for other people that wanted to use one and discovered that it seem to stick all the time: with a die grinder and a fine grade Emery cloth and made them so that they were easy to seal up and easy to use. Most of them that I clean anymore, rather than use a big propane torch, I put them in the bottom of my BBQ grill and turn it up on high for about an hour and that seems to burn all the grease out, then you gotta remember to be sure and scrub it out real good before you recoat it with perhaps Crisco. That was the recommended grease to use years ago, it does work, though there's other ones I understand that work just as good, coat it nice and even inside and out, place it in your BBQ grill up on top of the cooking grate and cook for about an hour at about 350 and it will have a nice even coating. Be sure and turn it upside down when you do it. This can be done in your regular oven, but it has a tendency to kind of smell the house up. It's even fine to wash it with real hot water, as long as you don't use any soap. They make a special chain link scrubber for cast iron fry pans, I own one and they work quite well, but it's not necessary. As a rule, hot water and a wash rag will clean it real fine
Squint