Hi Lewis,
Only time for a brief reply as I gotta get into work!!!
I've an office I do every month with this kind of film on many of the windows, although they are big panes I don't use the squeegee, I use a hand sprayer with a generic window cleaning spray (any of the main supermarkets own brand ones) and buff clean with a flat weave microfibre cloth.
for something like this they are better than scrim as they are a much softer material.
When the sun is at the right angle, all kinds of flaws in the coating show up anyway, but for me at least, done this way I've noticed minimal (if anything at all) damage to the surface.
Once an internal office type clean has been done, keeping them clean is child's play, and to be honest, you can whip through them ewasily as fast as you can with an applicator and a squeegee.
Ian
