How to get olive oil out of makeup brushes?

SO, I was cleaning my makeup brushes, and I start to do my foundation brushes and my kabuki brush, though when I'm done rinsing them, and I'm starting to blot them with a paper towel, I notice they feel oily. I set them upside down anyways and leave them for about two hours. When I come back and feel them, I notice they feel oddly oily, as I run my hands through the bristles, I feel an odd liquid-y feeling which I could tell is the olive oil. So I re-rinse them, and re-clean them (rub them in olive oil again) But when I'm done blotting them dry, I still feel oil! What do I do to get them out?