Where can I purchase Sugar-Free Lollipops?

My father is recovering from an illness and he's not allowed to eat yet. He had a gastric tube inserted and basically gets all of his nutrition, in liquid form, directly to his stomach. The occupational/speech therapist wants him to exercise his esophagus muscles to prepare him to begin eating again. Needless to say, it's pretty difficult to practice swallowing when you're not actually allowed to swallow anything. He's diabetic and can't have regular hard candy. I'm having a hard time finding sugar-free lollipops, which are safer for him because they have a stick he can hold onto. Help!