I finally invested in a nice eyeshadow brush from Sephora, and you guys, I still haven't washed it. It's been months. The poor thing has gone from gold glitter to dark brown eyeshadow and back again, and the only "cleaning" it's ever received is a vigorous brushing against the back of my hand to rid it of whatever color it used last. Incidentally, used makeup brushes collect all sorts of lovely things like dead skin cells. This can't go on.
I don't know about you, but I'd like to continue applying eyeshadow without developing a raging case of pinkeye — or worse, ocular tuberculosis, which is a thing I just invented to scare us all into submission — so I did a little research and here's what I learned. There are four household items you can use to clean your makeup brushes, and you're going to treat your them exactly like the thing that they're made of: hair.
1. Clarifying or baby shampoo
Fill a bowl with lukewarm water and a dollop of clarifying or baby shampoo. Swirl each brush around in the water until you've worked up a lather. You can use your fingers to lather up the brush, too; just be gentle with the bristles. Rinse beneath the faucet until the water runs clear.
2. Dish detergent
Not that you'd wash your hair in dish detergent, I hope, but if it's all you've got, it's a perfectly acceptable substitute for shampoo in the scenario above.
3. Basic soap
I'm talking unscented. Take that bar of soap, swirl your brush around on it like you're a barber in a good old-fashioned 1950s musical, and rinse out the lather.
4. A mild oil
What? Why is oil taking over the world? Because it's amazing, that's why. If you really like wearing makeup and your brushes are caked with the stuff, then you might want to grab yourself a few drops of olive or almond oil and start massaging all the gunk out of your brushes. Once the grime has dissolved, wash with one of the soapier options above.
No matter which method you use, do not let your brushes dry standing upward (hairs pointing toward the ceiling). According to The Beauty Department, the water will settle into the glue that's holding all the bristles together, and everything will start coming apart, and your life will be over. Lay your brushes on a towel, flat or on a gentle downward incline.
If after washing, the brush feels stiff and dry, it's perfectly acceptable to use a drop of conditioner on it — treat it like a tiny person's head! Rinse post-conditioning, of course. And try to clean your brushes about once a month. Remember: ocular tuberculosis.
(Stop everything, I just Googled it, it's a real thing. Disclaimer: You won't get it from dirty makeup brushes. BUT WHAT IF.)