<< Ribbet, then how DO you wash a cast iron pan or skillet, if you don't use soap? How do you get it clean? >>
Good question. The answer: Easily (Chrisrafter offered an effective, but more difficult solution)...
1) Put some water in the pan/pot while you're eating (or not, it's your call, and it rarely matters if pans are "well-seasoned".
2) When you're done eating, just rub it with a "plastic scrubber" (those little/round/orange/plastic thingies -- or something similar, with NO soap ).
3) That's it. Just hang the sucker up, and let it drip.
The point is: if cast-iron is "well-seasoned" (heat to "hot"/add vegetable oil/swish the oil around and let it smoke/wipe off), virtually nothing sticks to it, and you can use it in ANY environment.
Soap **removes/extracts** the oil. So, don't clean with soap (or, use it rarely, then re-season the pan/pot). We "season" our cast-iron 2-4 times a year (a trivial 5 minutes each time). Professionals like Chrisrafter might do it weekly, or with each cooking. In any case, it's a trivial exercise for cheap, indestructible, care-free, stick-free cookware.
BTW:
1) The TODAY show recently reviewed the "latest & greatest" kitchen gadgets. Among the $200+ electronic wizardry, and the coolest/newest gadgets was a humble, cast-iron frying pan (but not-yet black).
2) On the 2nd date with my wife, I brought her back to my place for dinner. She volunteered to clean up. After 30-40 minutes, I went in to find out why "cleaning up" was taking so long (I *was* anxious): She was scrubbing my cast-iron pans "shiny." I had to season them 2-3 times to recover.