OK, I don't know what the dry ice would do to improve the weed. Mold can be down right bad for your lungs. BUT, way back in the 70s, I would take the stems from my $65 kilo, blenderize them and stick them in a jar with just enough "el Cheapo" vodka to cover them. I'd let it sit for a few days and then strain out the stems and mix the liquid in with the weed. We would then spread it out thinly on cookie sheets to dry over night ( sometimes it took a day or so, depended on the temperature and the amount of vodka). Once it was dry enough to smoke, it was ready. THC is soluable in alcohol and when it evaporated, all the stem's THC was left on the weed. This was Mexican brick weed, so buds were smashed up against stems and the bud's THC would get on them. I believe it improved the quality. You might want to try it sometime.