Now, some people like to call this wonderful black stuff 'seasoning" on their pans. But I think its just an excuse because they have no idea how to get it off. I know what seasoning is. Seasoning is that beautiful black glossy finish on my cast iron. This, this is not seasoning.
The trick to getting this stuff off is simple. In fact, you need three things: baking soda, water, and elbow grease. Lots and lots of elbow grease.
The steps are easy. Make a paste with the baking soda and a tiny bit of water. Spread the paste over the areas on the pan that need to be cleaned and let the pan sit for a few minutes. When you finally remember to come back to the pan, use your fingers, a towel, a scrub brush, or any combination of these, to scrub off the black stuff. And here is where the elbow grease comes in! (And as far as I am concerned, this totally counts as your work out for the day!!!)
When you are all done, just wash your pan off with some soap and water!
This method, however, is far from perfect. Your pan will not look new at the end. It will never look new again, so just accept that fact and be happy with as much as you can off.
AND, your hands will be so nice and soft when you are done!