I used to use a pressure washer when I was a decorator, commercial work, stripping paint and mill scale from towers and so on.
5000 psi and several gallon a min through a needle jet
You could cut through a plank almost as fast as a chainsaw.
Using that baby 40 or 50ft up on scafolding was incredibly exhausting, because of the work, you couldn't hold it a nice easy position, often overhead or our to the side.
We could only use it for an hour at a time, you were so knackered after that your partner had to take over.
While you got dressed in dry clothes you recovered and made sure machine was kept fueled and had plenty of water.
Because you had to squeeze the trigger so hard to get full pressure your fingers ended out like sausages.
22 years later my fingers still go numb after holding my pole for 20 minutes...................err, I'd re-phrase that, but you all know what I'm on about
I've never used a pressure washer on the end of a pole, but I reckon if it were a long enough pole I'd love to film someone, they'd be like something out of a Norman Wisdom film
Ian