Personally, I think this is the best way to clean your make-up brushes. I have been searching online trying to find the best way to clean my make-up brushes but most of them requires buying professional make-up removers that can be expensive, or using johnson baby shampoo. I tried this tutorial from Michelle Phan and I have got to say this made my brushes clean and soft. All you need is extra virgin olive oil (which is great for waterproof make-up) and antibacterial soap. The products are inexpensive.
However, the problem I have is that my brushes takes ages to dry and I have yet to find a good solution for it.
I am not trying to promote Michelle Phan or have any intention of copyright but this video is a good tutorial and it is a recommendation for people try this.