Tadgh, yes I suppose your right really you can't push anything without an operational website
Seriously, I know we have opposing views, and yes I would agree if I used g101 at full strength on the same UPVC every month then at some point down the years their would be damage - which is where you are coming from, however, g101 is used as a diluted single shot application. From my end I need something that cleans off heavily soiling instantly and effectively with minimal effort, time is money and g101 ticks all the boxes.
If your cleaner can beat g101 for cleaning power I'd happily use it and recommend it.
Darran