I've never come up with a solution this problem, AJ (although, I never tried the sweater in the freezer thing, lol). I think you should try it and report back.
Sometimes this shedding thing goes away after a few wears, when the loose fibers work themselves out, but sometimes it never goes away. It's hard to tell for sure, all you can do is wait and see. I usually take a pass on shedding sweaters at the store because of that. BUT, I have found that if I wear a silky top underneath the shedding sweater, the shed is minimized (although, it doesn't go away completely). Raw silk won't work, it has to be slippery--like polyester, or satin-like, silk-cotton voile, etc--so there is less friction to pull the loose threads out of the knitting.