Far from an expert here, but my experiene with a bubble magic machine with 4 sizes of microns vs dry ice with same 4 size microns is that the yield is far far greater with the dry ice--like 10 times greater. The end results are a nice blonde color, but does shift to more green after sifting for a while. I just sift until the color starts to change some, then collect that and sift again until not much is falling. The trim/buds used were mostly dried. Using frozen fresh trim yielded far less.