Hello everyone is it a good thing to spray WD-40, breakfree, ect down the gas tube? Went to the range this weekend and there were about 5 quys clenaing there AR's in the parking lot and they were told to spray WD-40 or other solvents down the gas tube to clean all the carbon out of it . I was told the opposite to leave gas tube alone, are you supposed to clean gas tube?

