What windshield washer fluid do you use?

JD says cleaning Gator XUV835 polycarbonate windshield with regular windshield washer fluid will ruin it.

Um ... huh? First thing I did when I found the reservoir was fill it with the normal blue stuff. Now I'm supposed to drain it out and not use it, I suppose.

Instead, JD sells a $19 + SH, to clean it. Better not use the other stuff, they say.

Anyone paying 19 bucks to fill up their washer bottle!?

If not, what are you using, and to what result? Apparently this stuff is Lexan.

Thanks