Distilled water isn't strictly necessary unless you live in a place where it's necessary. :) Also, the only way you're going to get a good look at the rainbow greasy colours while still having enough time to actually wipe the windshield before it dries out is in indirect light or the garage. My comments have built-in failsafes. :)
.. I don't know any place locally here that sells squidgees small enough to do that. The real window-washer ones (bronze/brass with no cloth pad on them) aren't available around here either.
I find it extremely difficult to reach into the tough spots even with just my hands with a few layers of paper towel wrapped around them.. I just assumed that, at least for me, a squidgee would be even more difficult, which would lead to over-wiped surfaces (leaving nasty streaks.)
But hey, if you can fit your hands down there with a mini-squidgee.. :)