I bottle wines, but labels are labels, in my world...
My LHBS mentioned to me that they use the hot water with oxyclean trick, but for an extra boost of power, they add bleach (a cap-full, say, per 5 gallons of water). So, I tried this. Glad I did it outside- you never know with bleach. The solution, if you wait for the oxyclean to dissolve completely, bubbles furiously after adding bleach. I'm guessing it released oxygen, as I didn't die or get chemical burns from the invisible released gasses.
I didn't notice any improvement on the label removals.
I did notice this: Any paper with foil in it is going to be a PITA to remove. It'll leave paper fuzz attached to stubborn glue residue on the bottle. Plastic/vinyl labels are easy; once you get a corner up, they just peel right off.
The labels that come off, but leave a plastic-film type of residue that kinda bubbles up, come off best with stainless steel ribbon scrubbers. They're less than $1.00 each in Asian groceries (for some reason, Giant Eagle doesn't carry them). I use ultra-concentrated Dawn with that, just in case it might help.
A friend of mine is a jeweler- I'm going to have him try copious amounts of my mead, then convince him to let me try to use his sand blaster. At the very least, it'll be interesting.