Sorry Pastor Dave, but I really don't like using a shaker can, and never for a puppy. I know that it has been used in temperament tests, but that's not the same as how most people use it when "correcting" their dog. It was a widely used correction technique a lot of years ago, but we've learned more about dog behavior and positive training since then. Using a noise or a touch to get attention isn't a bad thing, but it should be used to gain attention only and then go on to positively teach the dog that paying attention to us is the best thing ever. If one does choose to use a shaker can to gain attention (only, and not my first choice), it should never touch the dog. If you have a rock solid dog it may do no harm. Other dogs become hand shy, noise phobic, they can begin to associate unpleasant things with their owners being near - I could list more. Most dogs find it highly aversive. Again - using it as a sound interrupter (softly and never on the dog) could be useful, but then it's important to make the transfer of attention to you the best thing ever. Rewarding what you want is how you get reliable behaviors. I also think there are much better and more effective means for gaining attention.
I've heard shaker can usage likened to clicker training. They are completely opposite. The shaker can is used to mark inappropriate behavior. A clicker marks appropriate behavior. Anyway ... I've used sound interrupters with great success with very anxious dogs, but it has to be done carefully and not as a punishment. Always show your dog what you DO want. As an aside - I've worked with dogs that find the noise of the clicker scary, so that can be a thing. In that case I use a marker word.