How often should you clean the barrel under your Free floating rail? I've had my rail (LaRue 13.2) installed for over a year now and I've never removed it. I don't know if I should worry about rust eventually, or if there is ever a real need to clean under it?

Does exposure to water, (rain, dropped in a puddle) warrant removing it and throughly cleaning under the rail and cleaning the barrel? (obviously this is preferred, I'm just asking if it is 100% necessary)

Also, do I have to remove it or can I clean it "good enough" through the holes in it?