This allows you to remove the debuff that gets applied to you when you get too low in Dalaran (so long as you become grounded and remain stationary). Essentially what you do is you find the invisible "border" of when you are given the debuff, and ascend and descend repeatedly below and above the border constantly removing and reapplying the debuff, until you no longer have it then you descend until you land and you are allowed to remain stationary on your flying mount. I can't promise this will work if you have high ms, though. Enjoy!
This only works if you land on your flying mount, and remain stationary.
Go afk in style.