Splatter & Spray Watercolor Techniques
A simulated aerosol attack!
If you want to get “into the process” you can grip the toothbrush close to the head and drag your thumbnail back across the bristles. It does alter the effect in a unique way, but extra clean up is needed.
Using the handle of a #5 round I started quickly raking across the bristles, releasing the paint in a spray. Pull straight back in a quick motion. Alter the speed of release and distance from the painting for variation.