I have been using a Vincent Longo brush cleaner every week. It doesn't wreck my brushes, but the only issue I have with it is the smell. It's just a strong rubbing alcoholesque smell that gets to me.
Still looking for my holy grail product. I have tried cleaning them with water and shampoo, by the way, and that method has always dried out my brushes...
I am also thinking about getting some makeup brush wipes from Sephora to use periodically throughout the week. Anyone used those before?