You can use the Empress Band to get a 3k xp bonus in a single hour if you're sneaky enough. It's highly situational though and you're better off just using it as you can.

First off, when you only have two charges remaining on it, use the band and log off for 16 hours. Log back on, get into a party, and use the final charge when your Dedication wears off. Now, trade the band to an outpost guard to get it recharged. The timer will start fresh, and bang, as long as you're getting 6k xp an hour, you've got a 3k bonus in a single hour.

I haven't personally been able to try it, but the theory is plausible.