The non-destructive method that is easiest to use is a can of Easy-Off or other lye-based oven cleaners, a garbage bag, and time.
Put the skillet in the garbage bag, spray top, bottom, and sides with oven cleaner, then tie the bag shut. The garbage bag keeps the oven cleaner wet so it keeps working longer. After 3-5 days you can remove the skillet (with gloves...Lye is nasty stuff on skin) and rinse with cold water and dish soap. If all the black-gunk didn't come off you can put it back in the bag and repeat the process or get a wire wheel for your drill and brush the little black crusties off.
Wipe dry and stick the skillet in a warm oven to dry completely then season how you want to.
Sandblasting while a quick and effective way to remove gunk from cast iron absolutely ruins collectable value. If the piece ever had it to begin with it won't after sandblasting.
Good luck and happy "stripping"!
--- In email@example.com, "Jim Teague" <cj3a1950@...> wrote:
> I'm pretty new to the forum but I would like to share what I did with a Yard Sale find last year.
> I took the skillet to a local service station that had a sand blaster. Had them hang it up and sand blast the entire skillet. I then took it home washed it with soap and water. It smoked a bit but following the directions from Lodge the skillet came out like a new one. ie. I dried it using the stove, coated it with cooking oil when it was cool enough to handle and baked it in the oven for an hour at 300 degrees. Hope this helps.