Truth be told, I can barely find my keys much less a clicker. I use the sound of my tongue making a clicking sound if I need to assimilate a clicker. However, I choose to mark appropriate behaviors in different ways.
How do you teach the dogs to comply?
Pawsitive tries to speak the dogs' language and teach them ours. If I go to France, I need to learn the language. Dogs associate the definition of a word with the behavior they are currently engaged in. (See Turid Rugaas and Dr. John Wright books for further information). In other words, if a puppy is standing at a distance looking at you, and you call him to "come"... you have just effectively taught him that come is standing at a distance looking at you. If, however, everytime the dog is within reach and coming towards you, you say "good come" with your hands on his collar, he will then associate come with you having your hands on his collar.
An untrained dog standing at a distance could be taught that specific behavior means "sit" if you were so inclined. If however, when the dog is actually in a sit position and you "mark" that behavior with a specific "good sit" along with a hand signal then the dog quickly learns that the behavior they were engaged in means exactly that. Gradually phase out the verbal when your dog understands it and use your hand signals.
You can effect any of those behaviors with or without treats and clickers. At Pawsitive, I choose to communicate with body language and hand signals. We teach them verbal commands for the purpose of the general public being able to also elicit responses when necessary and because understanding of verbal commands is a life skill the dog should be familiar with.