Why not use your favorite solvent?...MURIATIC ACID.
Funny you should mention pool acid ...
http://www4.picturepush.com/photo/a/...g/12898627.jpg

Just to report back on the hydrochloric acid, it didn't dissolve
the paper label any better than did the dish detergent solution.
http://www4.picturepush.com/photo/a/...g/12900797.jpg

But I really like how well the gasoline almost instantly removes
the gummy glue residue off the plastic bottles:
http://www5.picturepush.com/photo/a/...g/12900798.jpg

The results are clear plastic bottles with no labels or glue:
http://www1.picturepush.com/photo/a/...g/12900799.jpg