I never pick before or after or during. I have a pick and a brush and a rag. The only time I use any of these is when (rarely) when it gets too dirty to fire. Only at the range.
The main and best reason I carry a pick is for the off chance that I dry ball a load, (it can happen to anyone) trickle a little powder in the pan and poke it through the touch hole, a couple of pan loads, Ram the ball down tite, fire it off downrange (POP) that's the sound it'll make, and you're clear (check with the rammer to assure the ball did leave the weapon) to reload correctly, next time. Don't ask me how I know this!