TSP melts them off
For labels that are not self adhesive, those that were applied with
the water based glue, if you put them in a 5 gal bucket with
TSP (cleaner ) in solution, in about an hour they will roll off the bottle
no residue, the TSP melts the latex based glue
We do six bottle at a time, put them in go play winemaker for an hour
come back pull them out, wipe off label rinse and repeat.
For self adhesive I use Acetone , kinda strong method, but put the bottles
in the bucket, pour in the Acetone, just above the label, cover and wait, again these will roll off but you must wipe them with an clean rag with Acetone to be sure all the residue comes off. Pour Acetone back into the original container
when finished.
Be sure and do the Acetone outdoors