It's correct that blushing is usually caused by high humidity. If you live in Houston, it is a fairly common problem. You can buy retarder from Sig that is compatible with their dope. I have also used Acrylic lacquer retarder, obtained at automotive paint stores, on occasion an it works OK.
It's also true that you can get rid of the blush by spraying a coat of thinner on the painted finish on a dry day.