There are a few different ways to use duct tape, but some are more effective than others. While it might not seem effective at first, it is a powerful tool that can be used with any weapon to deal massive damage to your enemies. This is especially useful in boss battles, as duct tape is a great way to distract the enemy and get away with some serious damage. It also works well with weaponry that has a charge up time, like the Mega Hand. You can also use duct tape with any other weapon to refill ammo, which is an added benefit to having this unique weapon.
Duct tape can also be used with starter guns. It can make them both more powerful. Using a starter gun and a Sling can allow you to fire more frequently. Combining these two weapons can also save you time when fighting bosses and other enemies who tend to use bullet sponges. Another option is to combine two guns with the same duct tape to use one weapon as two. This will make both guns cost the same amount of ammo and will allow you to fire twice as much ammo as you would otherwise.