I tried boiling some rims at full boil for half an hour turning regularily, and some glue broke off, but a lot still stayed stuck. So I chucked it into a container of acetone for a couple of hours and viola! Pulled straight off and no glue left on the rims either.
Seems it depends what glue you use. I had in the past baked tyres in the oven at 110* and this worked ok too, but I didn't want to stink out mine again
