well i think thats what its called wheer they do a matt type finish on your dash that doesnt chip or anything needs some kind of high voltage device to do it though
To apply an electrostatic charge to the plastic, you need to rub it with something like a nylon cloth. Nobody seems to have mentioned doing this on a DIY basis (everybody seems to drop the flock on without attempting to create an electrostatic charge, and then everyone says "it looks better when the pros do it") but I've unintentionally 'charged' all sorts of things while trying to dry them. Fluff from the towel stands on end. That would be a good time to sprinkle on the flock material. Then you would re-charge and sprinkle again.
Otherwise I imagine you need to make a machine like the Van De Graff generator that we all remember from high school. Well, in that machine the insulating material transferred a charge to a metal sphere. What you want is just to transfer a charge onto the insulating material. Perhaps you could achieve this by mounting a buffing wheel onto a drill?