Originally Posted by John E
I always use Loctite on Italian- and French-threaded fixed cups, which are inherently self-loosening, i.e., they have a nasty habit of coming "un-fixed" under load. Anti-seize works great on properly-engineered bottom brackets (English and Swiss).
The common practice is to use a lock ring on the left side. Even so, the lock ring sometimes still comes loose. It's not a bad practice to loctite the lock ring ONLY, and anti-seize the BB threads inside the frame.