My own brushes are a random crew. M&S, Barbara Daly, Body Shop, No7. I wash in a very mild shampoo (like Aveda Shampure) and stand in a glass, brush side up, to dry.
I've just invested in some Real Teqhnique brushes for DD (Thank You BOGOHP and Boots points) so didn't cost me loads'n'loads but they were an investment.
How to clean them? They seem different to mine, smoother. I don't think they'll tolerate my sloppy cleaning methods