if it is just straight forward cleaning then WFP is by far the best method, pressure washer might be ok on cladding, not a lot of cop on windows though as you still have to clean them afterwards, the glass that is :
Advtantage with WFP is that you are using a brush and not a high pressure lance, its low pressure too of course so you are not affected the higher you go. pluss of course the pure water being used leaves everything clean.
If you are talking about cleaning up faded and old UPVC that has been weathered then you can use anything from T cut to Jif (ok, ok, Cif
)
Got to be quite labour intensive I would have thought though,
I can't comment any further on that myself as I haven't had to do it, quite a few on the forums have though, there have been quite a few threads on the topic.
Ian
