Cleaning caps
The way to clean caps is to hold the can upside down and press the cap, letting pressurized propellent do the job. NEVER put a cap in your mouth in an attempt to clear them, because that allows toxins to be absorbed by your lips (a vulnerable spot) and you can't blow hard enough to do anything good for the cap anyway. Tell everyone to quit it. There are much more interesting ways to absorb toxins, if that's what you're into. Some people report that soaking partly clogged caps in acetone (fingernail polish remover) sometimes helps if you do it before the paint is completely dry.