I seem to be going through disc brakes at a horrifying rate, not because they are worn but they seem to be getting contaminated and just stop working. It's happened on several bikes, the only common thing being cleaning them. The only thing I can think of that might be causing it is the brush I generally use to clean my bikes. I use the hope cleaning stuff.
Has anyone had similar problems and managed to save thir brakes? How? I've tried cleaning the rotors with isopropyl alcohol but it's no use!
A brand new pair of XT discs and calipers are about to go in the bin 
