The traditional way to clean cast iron pans is....
to place a large quantity of salt in the pan, like 3 Tbl, and use a paper towel to scrub the pan clean, the salt is an abrasive but doesn't remove the pan's seasoning. When it is clean, rinse in hot water (never using soap) and then put the pan back on the stove to warm with a Tbl of regular oil. When the pan is hot again, remove from heat, allow to cool and then rinse with hot water again and wipe with a paper towel. This way your cast iron pan stays seasoned. The salt also is a deterrent to bacteria.
If your pan wasn't seasoned well in the first place, perhaps you need to season it again - I'm not sure how to do this, perhaps someone else can help? I inherited my cast iron egg skillet so I just maintain it.
Another great trick, which for some reason my mom never felt compelled to share with me until a few years ago (all those wasted years of scouring pans -ahh!), is to soak pans that are really encrusted with baked on grime overnight with a Tbl of powdered dish detergent and the hottest water you have. The following morning, the baked on stuff just slips off and it is like a miracle! You cannot use this method with non stick pans, it will ruin the finish.
Hope these tips help you!