Get a piece of wood dowel, and cut a longitudinal slot down the middle to suit the width of the sandpaper/emery cloth strip that you have. Put one end of the sandpaper in the slot, then wind the sandpaper around the outside of the dowel - making sure that you wind it in the direction that will not unwind it. A combination of centrifugal force and the springiness of the sandpaper will regulate the amount of material removed. This handy little tool can also be used with the workpiece chucked in the lathe for polishing bores as well. Make a few different sizes for different size bores - 1/4" dia, 1/2" dia, 1" dia, etc.