"Heh heh, oh man, my brush water is getting dirty. That's awful. It's really time to change it. Why, there's so much pigment floating around in there, it's like cleaning my brush with another paint! Well, okay, not so much a paint, but definitely a...wash!!"
Here's a light first pass. Looks good! I did a little more thorough after this, knocking the brush around and causing splatter all over the place. And best of all, when I'm done-- my brush is clean! Ish.
You could do this responsibly by starting a two stage brush cleaning system-- rinse it off first in the "wash," then actually clean it in a cleaner cup.
And when you're knocking your brush around crazily making spatter? Watch out for the back splash.