If there are 100 posts in this thread --you will hear 100 different methods of seasoning cast iron cookware. I have my own method--but do not want to add more confusion.
The good thing about all of these different methods that are working for so many different people is that it is proof that seasoning cast iron is easy and has many different flexible methods.
When I purchase any cast iron cookware, new or used, I look at the original surface. Some cast iron is very rough, and some cast iron looks like polished glass. I buy the smoother pieces. I fry my eggs in cast iron every morning and flip the eggs to turn them over---however I started with a finely polished cast iron piece.
There are websites like
www.camp-cook.com that have more cast iron info than here at BBQ_Brethren--I would look to see what others say---then determine your own method.
This is some of my cast iron at the "Smokin' In The Oaks" KCBS competition last year in Penn Valley, CA. You can see that most of the cast iron is shiny black