Bisi's cast iron cleaning technique:
1. Heat oven to 300 F.
2. Use a plastic scrub brush and warm water to clean out the pan after use. The brush I use is for the cast iron pan only and nothing else. No soap touches it. The pan will still maintain a nice layer of greez after I'm done.
3. Turn the oven off once it's hit 300.
4. Place the "clean" pan face down on one of the oven racks.
5. Let it sit in there for at least 20 minutes, or just forget about it. The oven's off and it's drying out using the remaining heat so it'll be just fine in there.