I first read about it Jorge Cervantes indoor outdoor grow Bible.
I've done the dry ice and Tupperware trick, took 3 days for the dry ice to finish sublimating in the freezer.
I put broken dry ice on the bottom, used a piece of aluminum door screen and bent a tray to put the buds on. And snapped the lid on, poked like 2 small holes to vent. This contraption was put in a freezer and took 3 or 4 days to finish.
It's been a few years, and I wasn't impressed. The smoke was smooth, but the funky flavor man.. reminded me of my grandparents farm.