Cast iron pans are awesome for cooking, but decidedly less awesome to clean. If you're having trouble removing caked-on food and grease, some oatmeal can do the trick.
Madhu Shailesh shares this great tip on Snapguide. Once you've used a cast iron scraper to clear the pan of the largest food chunks, sprinkle in some quick oats and a little bit of water. Rubbing the oats around vigorously with your hands will create an oatmeal-like paste that can absorb the leftover grease without stripping the iron. Once you're finished cleaning the pan, try improving it with a flax seed oil seasoning
Clean A Cast Iron Pan in a Very Simple Way [Snapguide]