I use bacon grease or flax seed oil. Key is to get the pan good and warm, almost too hot to touch, and then a light coat of your chosen oil. Bake the stink out of it at 500 for an hour, upside down with a crappy cookie sheet or something underneath, let it cool until you can handle it with your bare hands, do it again three or four more times. The key is to go extremely light with the oil, as light as you can get and still get complete coverage. Wait until the wife is away for the day and open all the doors and windows because you will hotbox the **** out of your house.
Just a disclaimer, if it's a new pan I do the seasoning, if it's something I've been using and it's already been seasoned I just wash with water and a brush then stick it on the stove and heat it long enough to make sure it's dry.
Rock salt is good I just don't normally have some, I picked up a piece of stainless chain mail that is great with stuck on stuff https://www.amazon.com/Ringer-Original-Stainless-Cleaner-Patented/dp/B00FKBR1ZG but most of the time I just use a brush scrubber.I like to scrub with rock salt, unless it's super greasy and then I'll use a little soap.