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)
The environment can be larger than whatever system you drew a notional boundary around and still smaller than the universe, so not being able to reverse the universe isn't a problem. Here, I'll make it explicit: imagine it turns out that your "environment" is actually a Laplacian monstrosity! You're just a subsystem. All concerns about irreversibility are thenceforth questionable.
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.