The bane of a paintball player's existence is, without a doubt, broken paint. When a paintball breaks in your barrel, all chances of an accurate shot are out the window until you can clean your barrel. But you don't have the time to completely remove your barrel and pull a swab through it! You'll get lit up! So use the battle swab, simply push the battle swab in, pull it out, and continue playing, with a newly cleaned barrel.
This folds up easily to fit in your pocket, but there are a thousand ways to carry a battle swab within easy reach. Carry multiple ones, chances are, one of the other members on your paintball team will need one. Be the hero, carry two battle swabs.