I decided to try this brush cleanser just because I bought some Sonia Kashuk brushes, and I've been impressed with this product so far. It lasts a long time - I've washed all of my brushes, tools, etc countless times with this so far and still have 2/3 of the bottle left. It comes with a spray nozzle, which is great for getting the cleanser into the bristles and removing all types of makeup.
Sometimes I rinse my brushes and get them wet, then spray this on and lather them. I also like to spray a little bit into a dish of warm water and use that instead. Certain types of makeup are trickier to remove, like lip products or gel eye liner, but this cleanser always removes all residues and rinses away clean.
My brushes feel softer when I use this, than when I used to just use gentle face wash to clean them. It does seem to have some harsh chemicals in it and is mildly scented, but I'm always careful to not get it on my skin for too long and rinse it off my tools well, and it's never given me any kind of reaction.
For less than $10, this is a good investment if you are like me and regularly clean your makeup tools. It keeps my stuff in great condition and helps me feel like everything is sanitary. Plus, a little goes a long way, even when you're washing 10 different makeup brushes at once!