Don't let the labeling get to your head--while adult pacifiers are used in adult play, they are still a valuable sensory tool for older kids and adults with oral sensory needs. Plus, they're better for your teeth and easier to keep track of if they are sized appropriately for your mouth. People of all ages can use them!
Here's an article that explains medical use of pacifiers pretty well. (And for bottles and other "babyish" items,
here's an article on the effectiveness.)