Hi Mark and welcome to the nuthouse
And... Sarah.. thanks for the reminder!!!
I think that I recognise your name Mark. I am sure you have been in contact with me before.
Anyway as Sarah says WFP can be great for cleaning conservatories but it isn't a magic wand. Its just another very good tool of the trade. It will remove algea build up, moss etc but if the UPVC is very dirty with ingrained dark marks I am afraid that its good old elbow grease and the right cleaning solution. Even then they sometimes dont come up like new but you can make a great job of it.
We do loads of these and now with WFP we do 90% of them without ladders with great results and very much faster than before.
For the very awkward to get to cons roofs such as the ones that form a gulley where it jois the building you would really need a specialist set of cons roof ladder/crawlers which allow you to get up right on the roof. These cost around £500 to buy but are a good investment because it means that you can offer to do work that others without the right kit can't do and charge very well for it.
Watch those finials though. They are usually very flimsy and need a gentle touch.
Hmmm seems like a job for Sarah
Cheers
Andrew