I've had mine for over a year - they clean perfectly fine with just some water. you can get a bit messy with the lube, so i just jerk it before I shower. Take the fleshlight in the shower and rinse it out.
To keep the fleshlight in perfect condition, baby powder should be used on it, but I haven't bothered in a long time.
I actually took my fleshlight to the next level, though - and I modified it.
http://www.beerandshots.com/fleshlight/
Elliot Spitzer couldn't pay for suction as good as that thing gives.