Don't use the "Arts and Crafts" type hot melt glue.. Won't work..
Get a good hot melt for broadheads like Ferrule-tite, and there are others.
I have never stresses on cleaning them, but if I did, I would spray them and the insert with "Brake Cleaner" from the auto store. Quick and leaves them absolutely dry, clean and void of any residue.. Heck even acetone,leaves a residue behind, Solvents leave oil etc.
the thing I don't like about machined ferrules, is if they don't spin, I can't fixum.. One glued on with hot melt can always be adjusted.