"However, unsurprisingly - you don't actually get back (all of) the "real" coins that you sent your address - but instead, a tiny fraction of them, along with some coins from other accounts, seemingly sent through a mixing algorithm of some sort. (So your chances of getting "special" types of BitCoins back is slim, and there's likely to be bits of things like MasterCoins, and CounterParty tokens floating around, attaching themselves to random transactions). :)" - Tyson Key