Don't know 'bout you but I tried the Joker's vault of surprise when I had the chance. Not that I looted anything particularly interesting. At the end of round, the green guy tells you to come back every day. Question was:
How do the Hell on Earth do so?
Answer: Piece of cake! ^^, Duty mission (where the horrid PvP word appears twice) and click Vault >_<'
No get to your looting, bunch of Jawa!