Exclusively to rogues, or people with rogue alts, the Flamescarred Junkboxes are an interesting gamble of your time with the hopes of pocketpicking a mob that happens to have a spare poison, class-specific healing potion, valuable mat, or heaven forbid an epic.
What exactly do they drop? Well if you haven't clicked the wowhead link above, you should do so and have a look. There is a chance for a junkbox to drop an inscription material, which might net you 30-50g a piece, which isn't too shabby. There is also a chance to drop rare gems, which can never go unappreciated. But the best part is the Rogue-useable epics that also drop:
The Twilight Blade Isn't too shabby, however anyone capable of killing the Omnitron Defense System in BDW, is likely to choose the Organic Lifeform Inverter.
The Krol Decapitator On the other hand, is a viable purchase for any rogue going combat. Combat isn't very popular at the moment, but Blizz is still trying to tweak them, so this item will still sell.
Edit: It's a bit late now, but I realised this in the middle of Omnitron trash tonight: Rogues aren't the only class that can use the above two weapons, but clearly are the most likely to.
Spinerender Is one of two Epic throwing weapons available to rogues. The stats aren't terrible when compared to the DTA that drops in BoT, and would likely sell well too.
Worst case scenerio, you now have a BoE epic to do a multitude of things with, but likely will sell well on the AH. All of these items sell for 30k+ on my server, and sometimes are great flipping items (as most BoE's are). I picked up a Dragonwreck Throwing Axe for 12k back at the start of the expansion.
So, what's a good way to farm these junkboxes?
Wowhead's comments direct us to the troggs in Deepholm. However, since it's on Wowhead, how many rogues are going to be thinking the same thing and heading over there and farm those troggs? While I agree, the troggs are the best bet for these, since they are in close packs, I have an alternative for when the area is over farmed. The lost city of Tol'vir and Grim Batol.
Tol'vir and GB are the only instances that you do not need to kill any bosses to get access to all the trash mobs. You set the dungeon to normal so the mobs have less of a chance of aggroing, and you farm your little heart out. You can take all your gear off and aggro a boss and die, to get back to the start, and you have free reign on the entire instance. Actually, if you're brave, you could even go in and farm the trash in BoT in the first room, but something tells me you'd likely be spending more time avoiding trash mobs trodding over you, than actually picking pockets.
Any ways, that's my two-bits. Happy farming, and good luck.