Power washing emerald cedar hedge?...

Ive been told by two different people that removing the dead "inside" my hedge will help it grow. One person said they used a air compressor and the other said he uses a power washer. Has anyone tryed this or know anything about how it will effect my hedge? Any input is appriciated?
Thanks

 

At a much lower pressure, this can be quite effective. Butchart Gardens just finished a multiple day attack with an Air Spade on a compressor (at a reduced PSI) for this exact task. Too much pressure and you will injure the plant.