How do you clean rusted cast iron skillets?

http://www.hometalk.com/diy/clean/cast-iron-skillets/how-to-re-season-cast-iron-pots-1332408

Use a nylon scrubber (never metal) to clean out the rust. You may have to do this repeatedly. If it's badly rusted, put a small bit of cooking oil in the pan, add a generous amount of coarse salt and keep on scrubbing. Once it's all clean, dry it well, then season it. Melt a very small amount of lard (animal fat) in the pan and brush it all over the inside. Don't use too much - just enough to make the metal shine. Put it in a slow oven 200 degrees for at least two hours. It is now seasoned and useable. I usually do all my cast iron cookware at once, or as much as I can fit into the oven. I also often do it at the home of a friend whose electricity is included in her rent!

Try it

i use coca-cola and a wad of Aluminum foil then use cooking oil after it is washed out,just a light coating

This will help:

http://www.bonappetit.com/test-kitchen/how-to/article/cast-iron-pan-rust

Google has very good articles and videos.

http://www.thekitchn.com/how-to-restore-a-rusty-cast-iron-skillet-cleaning-lessons-from-the-kitchn-203086

I put mine in my oven on self clean and it came out like new. I seasoned it and it looks great.

Wash well using a metal scrubber. Rinse well. Dry. Wipe out any new rust and coat well with grease or oil. I usually use lard but I've used olive oil also. Bake at 250-400 degrees for an hour. I usually do it at 350 f.

For TouchUp I just wipe entire pan or a spot and get it real hot on a burner and let it sit to cool. A few of my pans and a shallow rimed griddle cane from my grandmothers grandma. Grandma was born in 1876. I don't know exactly when her grandma was born. Well kept and well used by several generations and they will go to my grandchildren that want them.