Hello there ♥ not washing your makeup brushes is like the equivalent of not washing your face.
I received a 50ml makeup brush cleanser (a free gift) from Etude House last year. I am not gonna lie, this is, *hands down* by far the best free gift I ever received from cosmetic stores. I usually clean my makeup brushes with dishwashing soap and olive oil before I even knew there was a makeup brush cleaner product in the market. I professed my love for this makeup brush cleanser.