Alternatively you could vent, shake, vent, shake, and repeat until it is where you want it, then return to 10 psi. I don't like that in practice because after a couple of times of doing it there is beer spraying out of the PRV when you vent the keg. If the keg isn't full you might have more luck with that.
Another option is to leave the PRV in the open position and let it go flat over a day or so, then put pressure back on. You can rig a type of airlock if you are concerned about air/critter ingress.