Now a tip for longevity of brushes which has been used by practising artists for years,by all means use the appropiate thinners depending on what type of paint you are using,but do not think that will clean your bruses in a sound fashion,it will not ! you see paint wriggles its way down to the ferrule of the brush no mater how good a quality or make,after a while it builds up so much that the hairs become caked at the ferrule and no matter how much you soak the brush it will not shift the debris.
There is a very simple solution to all of this,after painting rub some ordinary soap into the palm of your hand,now swish the bristles around and just see the amount of colour still within the brush that the thinners has left,this is the paint that does the damage,rinse through a few times repeating the procedure and finally shape up the bristles by hand,place the brush bristles upwards into a container such as a jam jar etc,all ready for next time you want to paint.
Forget the brush cleaners on the market,they are ok for a quick removal of some paint,but do the job properly and your valuable brushes will last for years.
PS-Dont forget this also applies to those expensive household brushes and paint rollers as well,use the same technique.