It seems to me, that instead of: " Drill a hole, insert the coupler so the threads are on the outside of the lid. Silicone it in place. Then as long as the screw cap had a gasket on it, your golden."
Wouldn't it be easier to just: "Drill 1inch hole, insert drilled stopper for airlock."
Not sure why the extra trouble....
Not trying to be a d*ck, just have a tendency to make things overcomplicated myself, and trying to prevent others from doiong the same.