In addition to the above: rubbing alcohol, acetone, cleaning solvent, or any other such substance. Some fine dust or dryer lint worked into the residue and then rubbed down with a paper towel, terry cloth, or other sort of rough cloth will remove it handily. In fact, one can skip the dust and cloth and just rub with one's finger or thumb.
It is the same adhesive as found on double back tape so there are dozens of ways to get it off a surface. A gun barrel is perhaps the easiest.
