It would certainly soften glue, but you may be better using either carburettor cleaner, cigarette lighter fluid or nail polish remover.
petrol
Before soaking metal jewerlry in WD40 to remove adhesive, test on a small area. This will prevent you from ruining the piece if the WD40 removes or damages the finish.
Try white vinegar, or WD40, or lemon juice, or sunscreen.
wd40.
wd40
Wd40
If it is ,man made surface, like plasic, that won't damage easily, I would suggest WD40. However, DO NOT use on wood, or any surface that you are even slightly worry will get damaged. If WD40 Is impracticable, I would suggest using warm, soapy water, and a nylon scouring pad.
WD40 and some elbow grease
Depends on what glue. Goof Off will work for many.
WD40 and a few kicks.
WD40 is good for removing most of the rust.
I've read WD40 works really well.