Disassemble the floss container and set the spool of floss aside. Close the floss container and tape down the two pencils side by side on the bottom of the floss container. This will form the handle of your grappling hook gun.
Using hot glue, stick a clothespin on top of the two pencils over the floss container. This clothespin will act as the trigger.
Finally, add the launch barrel previously assembled on top the taped-down pencils, on the opposite end from the handle with the rubber band draw facing the clothespin.