Flocking Flock

I'm trying to make some modelling flock, with only limited success. This is made from bits of a kitchen sponge, whizzed up in a blender, coloured with ordinary house paint kneaded through, dried in the oven and then ground again in a little electric coffee grinder. It's not utterly worthless, but I was hoping for a smaller grain size than this. Also, the sponge is yellow, so that affects the final…