Obsidium Sanctums 25 Heroic trash infinite farm

I haven't seen this here, and until our toons have become iLevel powerful enough, this may not have been possible.

I do this on my Death Knight, specced Blood for self-heals:

• Set to 25 Heroic Raid
• Enter Obsidium Sanctum
• Run up and agro Sartharion
• Run toward exit portal
• Kill everything (Watch curse of mending)
• Loot
• Exit instance
• Run back in without reset and all trash is back
• Rinse and repeat

I have pulled tons of greens and Frostweave from this. A bot would kill this.

I can't figure out why sometimes I have corpses inside to skin, when the 99% is a full reset.