What'd I tell you? Super simple. A drop of olive oil + a blob of your favorite deep cleanser and wah-lah, squeaky clean brushes! Remember to put only a drop of oil - think of ratio of 1:8.
Why use olive oil? Olive oil breaks down and dissolves makeup with ease, and it will condition your brushes as well. Why use face wash? Well, it's going on your face anyways. Pick your favorite one that really cleanses your face well.
Thank you for reading! Let me know if you try this, and how you like it.