I used to use ether to clean my brushes but I think a specific product should be better. This one cleans your brushes in an instant and has an anti-bacterial function as well.
What you have to do is this: take the brush you want to clean, spray it with this product (4 sprays should be ample), use a kleenex to swipe the brush onto softly. The result is a very clean brush with no hassle at all.
It doesn't get easier than this! :-)