If...you adjust the trigger mechanism properly, you only need to polish about .030" of the sear halves / surfaces that slide on each other.
DO NOT use Dremels or other hand grinders / tools with tiny , small dia. stones. I've never seen anyone that can hold a "FLAT" surface with a .25" dia. stone.
IF you feel the need, use proper tools. "FLAT" stones, flat table surfaces. Square blocks that support the items as you move them across the stones. fine sand paper.
The rubbing surfaces NEED to stay..flat and square with the axle / pin that it rotates on, for a proper sear polishing, and..."proper' action of the parts when complete..
Then, you can give the surfaces a light final polish with a large buffing wheel.
Mike