The smart thing would be to not let him in your clan in the first place during OSW. The next option would be tell him he was being kick as he was not probably vetted.
Why not let a noob clan join to give them a chance at OSW with some experienced players? Thats the entire point of this game. Plus all his kicking does means one of two things. A.) He's inactive (as has been said) or B.) He's a mole, which I kind of think he is solely from this thread.