The customer will Be over the moon with the results I’m Sure.
I doubt he is charging enough to really
Cover his time there, but Mayb he is?
For me, I would just put some virosol on the windows first, thorough scrub and rinse of everything, and then go back over glass only.
It would be just as good, and arguably better, as the windows will Stay cleaner for longer rather than having a lot of soap residue left.
Definitely Overkill in my opinion too.