While grabbing an estimate from my pal - Painter Bob - I noticed his paint brushes each had a single medium sized hole drilled in them above the metal casing - right under the wooden handle.   Bob drills holes into his brushes because he can hang them through a metal dowel or even wooden one - due to the expensive brushes he uses, he likes to be sure the bristles stay in tact and do not loose their shape.  He simply hangs them on the dowel, lays the dowel on top of a bucket during a break as well as once they are cleaned out, he hangs them to fully dry.  Just remember, this is also the clever painter who loves to RRR - he uses old rubber balls - inverts them and fills it with spackle - inverts it again when he is done, recycles the unused portion and rinses out the "halfed" rubber ball.  Simple, reduces waste and recycleable!  Thanks Bob for your clever tips!