Your face is clean when you put your make up on, right? Therefor, your make up brushes shouldn't get gunked up, right? So very wrong.
Like most women I've read about cleaning my make up brushes, but I didn't put much thought into it. I haven't dropped them in the toilet or anything, so they should be pretty clean. Yeah, no.
Today I was
1) Run your brushes under lukewarm water.
2) Put a little bit of gentle soap into your hand (baby soap or other similar soap) and swirl your brush in your hand.
3) Don't gross out by what you see. OK, that's not in the formal directions, but when you see what comes out, you will be grossed out.
4) Rinse under running water until water runs clear.
5) Lightly brush your now clean brushes on some paper towel.
6) Lay your brushes on a clean towel to air dry.
It doesn't take much time and I really recommend doing this. My blush brush was the worse. Clumps of things came out. No matter how clean your face is, you still have natural oils and things on your face, and they get into your brush.
You're supposed to do this weekly, but well, you probably aren't going to. Do it as often as you can. It really is healthier for your body. You wouldn't put a dirty toothbrush in your mouth. Don't use dirty brushes on your face either.