I used to be able to get this windshield washer fluid that was clear, no blue color. It worked great. Not sure what was in it, but it let the paint flow.
I have had a few issues with the blue colored fluid. Not sure of the brand but it was the cheapest on the shelf.
I have had good results with alcohol, distilled water. Micheal's has this stuff called flow control, it is a retardant for water based paints. Lets it flow before flashing off. If you use a brush, it really helps to keep the brush marks down.
Buzz.