I tried it once but it didn't really work very well. The buds froze solid and didn't really dry. It was fun to shatter the leaves off and it could even be used as a novel way to manicure but it was my understanding that it was used to quick dry the buds and it certainly didn't work at that. I did it in a small cooler with the lid cracked in my bedroom floor. It was a very effective roach motel, My guess is that they could "smell" the Co2 being released from the dry ice and were attracted to it in droves. I left it on the floor overnight and in the morning it had like 50+ dead cockroaches in there with my buds, Yummy. I then tried it in the freezer as described above for another 1.5 days when i took it out it was almost as wet as when i cut it down and the buds i had dried the traditional way were nearly dry.
So i wouldn't really reccomend it. My understanding of how the process was supposed to work as fairly straight forward, The theory in my understanding was that as the dry ice moved from solid to gas it created a flow of gas over the buds that had NO humidity as the C02 was dry.
I wrote it off as one of those Canna-Myths you hear so often. How can anything evaporate and dry out if it's frozen solid? If it is possible it's beyond me. I do not reccomend it.