1) Rub the interior of the skillet with shortening (not oil. Really lather it on thick.
2)Put the skillet-- shortening and all-- in a pre-heat 325 degree oven
3)Let it "bake" for approx. 1 hr.
4)While not a nasty smell it wouldn't be the world's nicest smell while it's baking.
5)After 1 hr. remove from oven. With paper towels wipe out any left over melted shortening. Allow to cool.
HOW TO CLEAN CAST IRON
1)NEVER put in dishwasher. NEVER allow it to soak.
2)Hand-wash using dish soap, very hot water and a scrub brush.
3)Rinse with very hot water. Dry immediately or else rust might set in
4)Pour a bit of veg. oil onto interior surface. With paper towel wipe the oil all over, till there is a nice,shinny coating of oil. (Don't be skimpy here with the oil. Better too much than too little)
5) Throw the oily papertowel(s) away.
That's it! I know it sounds like a lot but in real life you're only looking at 3 or 4 minutes.
Remember: over time your cast iron skillet should develop a wonderful black color. This is always a mark of a well maintained piece of cast-iron.
(P.S. Never cook things like tomatoes or other high acid foods in cast iron. The food will come out tasting real funky, and the acid from the tomatoes (or whatever) sure won't do the cast iron any good)
Hmmm...is that why "cowboy" beef stew doesn't have tomatoes in it?