Ugur

So this involves having at least 2 different lv70 characters able to defeat Don Carlos on heroic and one of them needs to be able to disenchant lv70 blues. (This is only going to work as long as the event with him lasts.)

I did this with my wife today (Holy/Shadow priests.)

Go into Heroic Hillsbrad, and right along the road you will find Don Carlos and his coyote. We would stand at max range, and dps the coyote first, then Don Carlos (Hits for about 1.9k-2k dmg at ranged, doesnt attack very often, nets and scatter shots). He drops Don Carlos' Famous Hat. Now this is a neat little hat to begin with, but here comes the fun. Not unique, and disenchantable.

After killing Don Carlos you will have an ID saved to the instance. Exit the instance, change the difficulty to normal, reset all instances, change difficulty back to heroic, and ta-da, your raid ID is erased and Don Carlos is back alive in the instance ready to be killed for another hat to be disenchanted

Rinse, repeat, and roll in your large prismatic shards.