It's the nature of movies (and other entertainment) to skip over the dirty chores or mundane parts of life, unless it's important to the plot.
A film is composed of many, many takes, spliced together. No doubt that lots of relights and pipe cleaning take place between shots, in order to convey the image that the actor is effortlessly and cleanly smoking throughout the scene.
Perhaps the most elegant thing to do with a pipe, by modern sensibilities, would be to simply use it as a prop and not fill or light it at all. But screw that, we want to smoke! So focus on better technique like taking smaller puffs, spaced out a little to reduce moisture buildup. Relights are no problem, use them for dramatic pauses. Then clean your pipes out of the sight of anyone else.
