Yep, keep turning it until it stops - then turn one-quarter revolution counter-clockwise & leave it alone. It will never loosen from that point - but it sure makes it easier to remove when using hot primers and hot powders for lengthy range spells. Walmart sells the tube of Slick 50 One Grease in their automotive department. I'm about to try it because CVA changed their ML grease formula recently& it's not as easy to work with anymore. I'll know more about how wellthe Slick 50works in another week or-so. But according to users here, it'svery heat resistant, costeffective -- plus multi-purpose use.
Take that breechplug underneath your truck with you.

Shoot three shots of grease into yourtruck ball joints - one shotonto the threads of your ML breechplug.