If you use a pressure washer to clean a conservatory you will invalidate any guarantee, it doesn't matter what pressure you use. Hence it is probably not advisable...
Mind you, I am just a pressure washing monkey from the other section and you guys are far more 'technical' than us 
Be carefull with them Shurflos then ,they're 100 PSI !!!!
probably similar spec to your pressure washer then
Hang on, you said don't use any pressure. I'm pointing out a Shurflo is 100 PSI. Whats the safe pressure a conny can withstand ?
why are you determined to act like a smart ar#e
I just offered a bit of advice as we work for local installer
Using a 'pressure washer' invalidates guarantee doesn't matter flow rates , reduced revs etc its a pressure washer full stop and why on earth would anyone use a pressure washer if you was running it at 100 psi as it would be pointless, Anyway you carry on.