After using non-stick for years, I recently bought two cast iron pans and have been learning the ins and outs of the cast iron skillet. Just one question, what oils do you guys usually use in yours? I have a large tub of Olive Oil from Costco that I'm trying to burn through. I know it's not ideal for the type of heat I'm getting from cast iron. I bought it in my non-stick days, what should my next purchase be?
Once it's seasoned, using whatever oil to keep it maintained after you clean and dry it is fine in my experience. I usually buy cheap sunflower oil and add a thin layer after cleaning and then heating to make sure all of the water is evaporated off.
Also, just making sure we're all on the same page that soap on a properly seasoned cast iron is actually fine - it's not mandatory but anyone on fucking reddit or YouTube telling you it ruins the pan is an idiot. So many people think that a "seasoned" cast iron means you don't have to clean it other than wiping it out after cooking in it or just using salt and then they're just cooking in rancid fats, oils, proteins, etc. that cake up over years. For the love of god, do not do this. Cast irons are not some magical instrument. Just clean it like a normal pan with soap and water, dry it after (by hand or preferably by heat) until all water is off of it and it's bone dry, and add a thin layer of fat / oil and let it air dry / absorb in. If you do this every time you use it, you shouldn't see its ability to cook nor its appearance turn to shit over time and it also means you don't have to do a full reseason every year (which it seems a lot of people think is a normal thing to do?).
To my knowledge, salt rubs are only ever needed if there's something SUPER stubborn or if you need to break shit down for a reseason. But if you just clean it normally and make sure to dry it well, rarely do issues build up enough to need that.
My ex had a massive collection of cast irons she found over years at thrift stores and yard sales that she took rust off of, cleaned up, reseasoned, and then brought back to life. The above was how she taught me to take care of them and how I took care of multiple cast irons for 4 years without any issues. I've done a small salt rub using table salt maybe once to get some burnt pieces of chicken off.