Loctite is one option for Italian BB's, you can also use teflon tape or just grease it and honk on it. However, I'm a little unclear on why you mention stripping the lock ring, it's the R side that's a problem, the L is fine and doesn't need any more torque than normal.

Also, once you get it in there good, never take it out unless you have to replace it. If it's a loose ball BB, just clean it out and repack it from the other side. It's a little awkward to do but it beats having it fall out. I may be the only one on earth weird enough to do it, but with cartridge Italian BB's I install them backwards so the main unit goes in on the L side, which is properly threaded. It seems to work fine.