That is exactly what everyone is doing to find pearls :) Ive found quite a few myself, and I know many other users have found plenty more!
Good thinking, go find some loot :P
Btw, a couple tips if you plan on farming the boxes:
Do not progress story to find bloodwings bloody feathers as it will unlock the doors containing the animals, making your job a little bit harder. Less mobs, quicker runs. If you have the "Creature Slaughter Dome" Dlc, and can access the "Natural Selection Annex", you should start there, a lot quicker :P Also, don't pick up the quest items for "Doctor's Orders" as their placement has a direct correlation to the LLMs spawning in the boxes.
Good luck :)
Are you serious? I picked up 2 of the 4 quest items. So I wont get all four legendary loot midgets now? --- I have Dysarthria. It's a Speech problem. Your question is answered now.