If you had a typical custom made flintlock which has the vent hole going directly into the bore thru the barrel wall, the location of the stuck jag would determine whether the "shoot it out with some trickled powder" method would work or not.
If the jag was pushed slightly past the vent, blocking off the vent hole from the barrel, it is unlikely that any powder would be able to get under the jag so the explosion would force the jag out.
If the jag was above the vent hole then the trickle method would work fine.
(By the way, this trickle method doesn't put enough powder in the barrel to possibly damage it.
It's not like loading 10-90 grains of powder (which might damage the barrel if the jag wasn't shoved against the powder charge.)
With your Pedersoli, I think it has a flame channel that comes into the bore at the rear.
If this is the case, pouring some powder into the vent hole and firing it should do a good job of blowing the jag out.
Just be careful.
Although the small amount of powder is not enough to make much more than a loud "PUTT" when it fires, that's still enough to drive the jag thru a hunk of dry-wall.