Just to clarify, its 500l tank of pure and yes pure water cleaning does help the windows to stay cleaner for longer. Thats what i have found to be the case along with the technical understanding of removing the soapy residue left from traditional cleaning. I even made this point with one of my customers by wfp one downstairs window and blading the other downstair window on the same facing wall. Four weeks later one window was clearly cleaner than the other.
Just because ive been able to knock out 30 or more houses in a day doesnt mean quality suffers and certainly not done on a slow flow or there would be no chance of getting that many houses cleaned in a day.
Its all about technique, type of windows being cleaned and size of houses etc.
Or in comparison to trad working. You could mop a window, put mop back into bucket on belt. Then take out the squeegee and blade the window and put away. Take out the scrim n detail the window and finally wet wag and wipe the sill. OR mop n blade in each hand and mop n blade at the same time. Put away n take both cloths out n detail n wipe sill n put away. Pending how you work and the technique employed one is more productive than the other but you wouldnt say quality suffers on either.
But thats just a side point
Before i switched over i couldnt understand why anybody would want to use wfp because surely it cant clean as good as being close to the window. I also liked it when some new chaps tried coming into my areas with new fancy van setups on wfp because i knew i would end up with a good portion of their work. Yep, it actually meant more work for me, no Bull!!
It was only because a friend i helped switched on to it that i had no choice but to use it. After 2 or 3 months i was hooked and wanted to invest in it myself and ive not looked back since. Realising that i had taken other peoples work because of user error and not directly the equipment fault. So soon realising that all the negative hype about wfp was a load of rubbish