Here is a goal: Clean cast iron

How would you accomplish this goal?

Options are:
[a]. Clean cast-iron skillet after every use. Wipe interior surface of still-warm skillet with paper towels to remove any excess food and oil. Rinse under hot running water, scrubbing with nonmetal brush or nonabrasive scrub pad to remove any traces of food. (Use small amount of soap if you like; rinse well..
[b]. Clean cast-iron skillet after every use. Wipe interior surface of still-warm skillet with paper towels to remove any excess food and oil. Rinse under hot running water, scrubbing with metal brush or soft scrub cleaning pad to remove any traces of food. (Use small amount of soap if you like; rinse well..
[a].