Someone bought me a cast iron pan a few months ago and told me to only season the first time. I know differently know, but in the interim, the pan has gotten rusty. Prior to today, I didn't know about letting the pan dry in the oven, so I missed that step as well. I've only used the pan a handful of times. Am I out of luck or can you tell me how to get the rust off? Thanx for any advice.