Salt Scrub
While the pan is still warm, add a small handful of kosher salt. Then, using a paper towel and firm pressure, rub out any food particles in a circular motion. Empty the remnants into a compost bin or trash can and wipe the cast iron with a clean, lint-free kitchen towel to ensure all salt particles and food bits are gone.
Warm, Soapy Water and Palm Brush
Make a batch of warm, soapy water with dish soap. Using a dish brush about the size of your palm and the soapy water, clean the food particles off of the cast iron. Wipe the cast iron down thoroughly with a clean, lint-free kitchen towel, leaving no trace of water behind.