You don't need a specialized product (like Goo Gone several comments mention) to remove sticky residue. Any kind of cooking oil will do. I usually use a small dab of whatever is on hand (which in my house is olive oil, but avocado, canola, corn, etc would also be fine). Start with a very small amount, like one drop: a little can go a long way and it can be a huge mess if you overestimate how much you need. Rub it in with your finger and the gunk should come right up. Paper towel the rest off. Repeat if necessary. Extra bad spots might require a touch of gentle fingernail action.