Hai guys, this is SWIM's first post. He's just an amateur kitchen kemist that has been lurking these forums for quite a while now. Let SWIM point out upfront that he does not have any experience with DCM.
From what SWIM's been reading, it should be very possible to use DCM in the extraction stage using the CLLE (after proper defatting), after which one would distill the DCM until a small concentrated DMT-rich amount is left over, due to DCM's BP being lower than that of DMT.
Once SWIY reaches that stage, one would add another solvent, like cold acetone (or maybe Heptane). until the freshly added solvent starts to distill, one would let it evaporate.
SWIM's guess is, if left over with a lot of gunk, either the defatting didnt go optimal, or the destillation process was run for too long. e.g. dry-cooking (note the use of 'guess' xD)
SWIM thinks it was ron69 that pointed these techniques out, and has the most experience with this kind of thing, so maybe ask him for more detailed info.