When you use a key on a chest it should show you 3 options, you can only choose 1 of them.
This way you get a bit better chance at getting what you actually want, without potentially grinding for weeks and just giving up (Like I have)
I'm pretty sure many people would agree that shoulder grinding is a terrible thing, from my experience, there is nobody calling out for pledge groups in zone chat, and even queuing as my healer for pledge dungeons I can sit in queue for 20+ minutes and never get in.
So from what I can see, nobody is farming these things at all. Maybe time for a change?