Remove cooldown on Wormhole Generator: Pandaria and other items

Simple exploit I noticed today.

1. Cast Wormhole Generator: Pandaria (15m cooldown)
2. Join an arena (2s work fine and often have almost no wait times)
3. Leave/complete arena, doesn't matter. 
4. No cooldown on the Wormhole Generator: Pandaria anymore. 

Very minor exploit, but nifty if you have a friend available and want to quickly get across Pandaria. This does not work on the Northrend equivalent, or any other Engineering items that I have tried, but does on appearance items with 15 minutes or less on their cooldowns, which probably has something to do with the cooldown timers and arenas resetting them.

Feel free to post other items that you can use this with, or any other uses you find for it that may be more helpful, but it seems to work with items with a