I do it in sections and rinse as I go. Roof, Rear Bumper/Screen, Front Screen/Bumper, Drivers Side, Passenger Side, Wheels.
Thats my routine, this stops the shampoo/water drying on leaving water marks, probably not very noticeable on white, but still.
Pressure wash is fine, alot of people use them, no problems with them if used correctly, and not too close to paint for long periods..