The Lewis remover does a great job - especially on the forcing cone.
For the bore, I do use the strands of copper/brass Chore Boy scourging pads wrapped in an old bore brush..........it'll pull long strips of lead right out of the bore landings.
No steel wool. You can use copper Chore-boy from your local grocer. Be sure its soap free. Wrap the Chore-boy around an old brass bristle brush. Pull it partially into the forcing cone and then spin it.