I oil after assembly from the dial side of the movement. lots of different advice on this subject, including the use of epilame.
Certainly on a high beat, I don't find the need to use epilame on the pallet stones.
Another way of applying oil to the pallet stones is to lubricate the first couple of locking and inpulse faces of the escape wheel and let it run.
I tend to oil the pallet stones themselves.
I Oil the stone ends while removed, seems I can always reach them that way, and I can do it more precisely. Since over oiling can cause running issues.