I would add that peanut oil is a better choice than veg. Idf allergic, olive oil. My wok always has a coat of peanut oil, it has a higher burn degree to it.

Take a green scouring pad (no soap!) and scrub with warm water. Dry with paper towels, then thinly coat with vegetable oil. Place in 300 degree oven for an hour. Wipe with paper towels after it has cooled.

http://www.food52.com/foodpickle/241-what-s-the-best-way-to-rem

http://www.food52.com/foodpickle/149-what-are-the-most-importan

Adding to my original comments above about Vegetable oil and salt, I just got off the phone with my Brother and he swears that rubbing an onion on the rust, will cause it to flake off. He swears!! ; )

Absolutely it can be rescued! Step one, scrub (don't scour) in hot soapy water with a plastic scrubbing tool. Rinse and burn dry on a hot gas hub. Using paper towel, rub it on all sides with vegetable oil. Step two; fry some bacon in it, eat the bacon, pour of the fat, rub the inside with coarse salt---a paper towel works fine for this. Repeat step two as needed. It builds up a protective almost non-stick "seasoning". Cast iron is great for its conductivity, but you don't want a ferrous taste in your foods. Personally I don't subscribe to the idea that all you need to do to clean such a pan is to rub it with salt. But repeated use with fatty things like bacon or fried chicken will help its life in your kitchen. They are built to last.

How rusty is it? Vegetable oil and plain table salt will remove the rust, but you have to use a little elbow grease along with it..