if you are using Acrylic paint, you might want to look at getting some Slo-dri and/or Flow Aid
Acrylic "tip dries" which is a form of clogging, if it is sprayed too thick or at too high an air pressure
using the Flow Aid lets the airbrush be set at a lower pressure,,,,and the Slo dri lets us spray a thinner color coat,,,,,,,,both of those keep the cotton swab full of airbrush cleaner away from the tip a bit longer during use (we can't fully eliminate it)