tips for stain (paint?) removal on polyester and cotton garments

Hi all, I went for a bike ride the other day and I somehow got gray splatters of some kind all over my clothes, both polyester and cotton (some Patagonia baggies, an osprey bag, and a favorite t shirt). This is the first time ive encountered this kind of stain while biking and I'm pretty upset. I am usually pretty good at getting stains out but these seem to be some kind of paint that I can't fully remove; picking at it will partially lift the top more 3-dimensional part but I am unsure of what to do to get the rest out, specifically between the fibers. It might be latex paint, it was slightly tacky when it hadn't set fully. Unfortunately it's hardened as I only noticed after I had finished biking, which could have been multiple hours after this occurred. So far I've tried just water, hand soap and water, dish soap and water, the washing machine, rubbing alcohol, and vinegar with no luck. My next guess is acetone, but does anyone else have any tips or suggestions?