Oskar Barnack knew what he was doing, why make life difficult?
And second the comment about buttery fingers -- no no no.
He may have known what he was doing when he started out with bulk loaded film in Leica cassettes, but when the standard cassette and film leader came into being his ideas kind of got left behind. I recommend washing your hands for all sorts of reasons (what are your sticky fingers doing to the outside of the camera and lens?), but even sticky fingers only ever go onto the unused first frame, its not like you can gunk up the whole film, or am I being overly optimistic?