I'm pretty sure I don't... Wikipedia: "Viewed in isolation, the system's dynamics are non-unitary (although the combined system plus environment evolves in a unitary fashion). Thus the dynamics of the system alone, treated in isolation from the environment, are irreversible. As with any coupling, entanglements are generated between the system and environment, which have the effect of sharing quantum information with—or transferring it to—the surroundings."
If you draw a notional, boundary around a system that is embedded in an environment and consider it in isolation, then you introduce an asymmetry due to the information lost crossing the boundary.
The system+environment evolves in a unitary fashion, but you can't do anything to reverse the universe.
The only hope of reversing is a system is if it actually is isolated...inot interacting with with an environment.
(relevance to quantum computing)
http://www.dailycamera.com/boulder-county-news/ci_18282009?source=most_viewed
I'd imagine the efficacy is halfway between proper cryonics and embalming and burying; the more interesting part may be the festival. Nederland is a small town 20 miles from Boulder, CO. I doubt the festival attendees are cryonics advocates, but they don't seem prone to the negative associations corpsicles often raise. Perhaps it's just because Boulder, Colorado is full of weirdos, but I wonder if there are more exploitable effects in play.