Instead, you'll have to get them through specialty shops, at dog shows, through clicker trainers, or from the Web. Some people use other tools instead of the clicker. Whistles, for example, are used frequently by people who are training animals to work at a distance. Flashlights are used by people working with deaf animals. If you choose a verbal marker, choose a sound like a cluck, rather than a word.
Some dogs are afraid of the sound of the clicker.
There are a couple of solutions to this. One solution is to put several strips of adhesive tape over the dimpled end of the clicker. The more layers of tape, the softer the click. As the dog becomes used to the sound, you can begin removing layers of tape. Another solution is to use a different marker.