invest the 20 bucks in locking coupler for the grease gun they are well worth it and buy a good grease gun like a Lincoln plus a box of zerts
The locking coupler I use is a South African design that was from either Northern Tool or Gemplers with one release lever. I have not seen a 2 handle type. Sounds even better, who makes it? One thing is for sure, a locking coupler is highly desirable.