While I was browsing Michael's recently, I found this brush washer in the art supplies and thought it would probably work for makeup brushes as well. It was around $5, so I picked it up, even though I'm sure this would be very simple to recreate.
I put a few drops of Dr Bronners soap in the jar along with a bit of a brush shampoo I don't care for and am trying to finish. Then I ran warm water until just the top of the wire mesh was sticking out above the water level. After that I basically just swirled each of my dirty brushes around on the mesh, which worked to gently splay out the hairs to get the cleanser throughout the brush. I was washing about 3/4 of my brushes this time, and even including dense synthetic foundation brushes, eye brushes with bright colored cream products in them, and lip brushes, I think it took around fifteen minutes.Because the mesh is above the bottom of the jar, the pigments can fall to the bottom and not inhibit the cleaning process for the brushes after. As a result of that, I never got to a point where I needed to change the water in order to keep getting effective results.