I wonder if that would be possible in a decentralized way, too? Atomic coin laundry...
As far as I can tell, it is either efficient or decentralized.
However, I don't see a problem with using laundry operators as long as no trust is required. I recently described a better approach involving blind signatures, by the way.
Suppose you see many operators and many participants available on some p2p network. You pick some and mix your coins with them.
It sounds decentralized enough for my taste.
A challenge with blind signature-based p2p mixing is quality control, basically you want to know whether you're mixing coins with real people or those were only fakes. I think it is doable if it is used together with some kind of WoT.
For example, WoT member will announce that he got his coins mixed. If many announce that, you can assume that quality was good.
