It works... first time I ran it I figured I must have killed every mosquito around.  I might have the advantage that there really are no other lights on around it, and I used that chemical attractant with it.  Very happy with the killing results.  However, I feel there are more mosquitos out there than this thing could ever kill alone.  It has killed thousands this summer, so we will see.  And ya I use my hose to clean it, with the gentle small droplets of water.  I figure so long as it is not plugged in and will not be run wet, spraying it down gently is just like the rain.