I do a lot of projects with recycled soda bottles. The best solution I've found is acetone (do this with plenty of ventilation and away from sources of ignition). Wet a cotton swap with acetone and rub it on the residue. Let it sit for a minute and repeat. It takes a few passes, but it does a good job of cleaning off the adhesive.
Goo Gone (and probably other similar adhesive removers), also works, but not as fast. The acetone seems to soak through the residual label, softening everything faster. The Goo Gone seems to need to wick in through exposed edges. Like acetone, it takes a number of applications to get everything off. The adhesive removers also tend to be more expensive than acetone, and some leave an oily residue that takes an extra cleaning step.