I'm thinking that this wasn't a good idea, or necessary. There was a small drip, but rather than try tightening (or if the threads were worn/stretched, replacing), the plumber used silicone caulk, saying that it would be able to be "broken" easily if I need to access it in the future. But even if that, will I be able to re-tighten it after? It would be hard to remove from the threads, wouldn't it be?