Don’t waste your money on expensive cleaner that is specifically for your make-up brushes! It is a total gimmick.
I use a bottle of Tresemme shampoo to clean them and then I use a cheap conditioner to moisturize the bristles. I wash my brushes once a week. I pour a glob of shampoo into the sink and ‘twirl’ the brushes around until the foundation/whatnot is out. After shampooing, I run them under water and squeeze everything out as best I can. I use about a pea-sized amount of conditioner after they’re clean. I then repeat the washing/squeezing. Once the conditioner is out I squeeze out the water and lay them on a clean hand towel to dry.
I have heard Dawn and olive oil work too.
What do you use to clean your make-up brushes?