Don't you mean reversible?
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."
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.