Windex and Simple Green (and the Clorox stuff) all can be used to remove dried on Acrylic paint and Future
so, I don't use any of the three as a thinner,,,,,,,,,one of the many reasons I had for switching from Enamels was that coat # 2 wouldn't eat at coat #1 anymore,,,,,,a common problem I had when brush painting Enamel over Enamel
do a test,,,,,,paint a 1" by 1" square of plastic, or the inside of a wing, etc, with Acrylic paint,,,,,,,then mix up some different color (red over white?) with Windex, etc, as your thinner,,,paint your red over your white with a brush, nice and carefully, as if it is a $100 model,,,,,,,,then look at the pink streaks you now have if your brush "cross-over stroked" anywhere at all
even if you do use Windshield Washer Fluid,,,,,,,make sure you use the plain stuff, not the bug remover strength,,,,those are too strong also
I tried all the cheap substitutes,,,,,,and the only non-matching factory thinner I keep around now is some Distilled water,,,,and I don't even use that alone, only as a mixer with Factory thinner and retarder
I know that this causes me to have 4 different Acrylic thinners around,,,,,but, if one line had all the correct colors, I would have only one
Rex