Hey the OP asked about fresh trim for dryice instead of regular ice method? I'm curious about this too, anybody know?
Fresh trim could be used for sure, but frozen fresh trim would be better I am guessing, and dry frozen trim might be best(may be too brittle, don't know for sure)
The idea behind the ice water for bubblehash, I read years ago, was to make the stalks of the capitate-stalked trichomes brittle. Thereby the gland heads can be efficiently broken off of the leaf surface. And being heavier than water, they sink to the bottom of the bubblebag.
So I am guessing that the dry ice method of extraction relies on cooling the air surrounding the glands, thus making the stalks brittle, etc.
If we do it with wet trim, we require extra cooling, extra work to produce the same effect.
Wet stuff wants to bend more than break I have found.