What I use for removing stubborn labels is WD40...a good soaking first in warm water to start things off so to speak and then once the majority of the label is no longer attached to said bottle, give it a blast of WD40, "work" it into the label-bits and off it comes. Some of the little blighters
do need to be coaxed a bit, but it does work. There's nothing sinister in the stuff, just pongs a bit!
Only had one failure and in the end, the bottle - with label still attached - went into the recycling bin...in a million pieces

. The label won the battle but
I won the war!
Nana Caz