You could probably put a headless wood screw into your plug stock, and chuck that up in a cordless drill to shape your wooden plugs on a belt sander. Then just trim off the screwed up end when you're done. The old hand drill lathe technique. If you can't just grab the whole work piece in the chuck's jaws. Then trim it off once tapered. Drills are better at holding stuff and spinning it around than I am. One dowel should net you close to a gross of straw plugs I figure.