Using a product like "goo gone" or mineral spirits or alcohol soaked in a rag, just wrap the soaked rag around the bars, let it sit for about 10 minutes, and then rub the softened adhesive off with the same or a different rag. Should take a maximum of 20 minutes and a little elbow grease.

Maybe you can just wet the adhesive with this stuff to soak it, but the key is to give it a good soak with the solvent (the universal principle for dissolving/softening anything that you're trying to clean - like setting dishes in water before scrubbing them), and the saturated rag, wrapped around the bar, will probably do that better than just trying to wet the bar and watching the solvent drip off.

Light oil will probably work too, but the above I know from experience will work. You'd probaby have to clean up the oil with some other solvent (citrus?) before wrapping and using them anyway.