I have to pick the vent on occasion when it's fairly hot and humid and I've had a flash in the pan. I have several, the easiest to use being a thin rod of steel mounted in a piece of antler. I also have one of those finely tapered wrought-iron picks that seems to help clean fouling from the vent.
I don't know about the rules regarding feathers in NC, but I keep meaning to try using a feather in the vent when loading, to cast a channel into the packed powder (and to keep the vent clear of fouling simultaneously).