This is a sneaking mission, agent. You've been cleared to take the Super Soaker Bottle Shot pistol with you, though how many enemies you'll be able to get wet depends on what kind of bottle you find. That's right, you'll have to procure your own ammunition on-site. Use whatever you can find: Any plastic screw-top bottle with a capacity of two liters or less should be perfect. Just screw it on there, pump the Bottle Shot, and blast anyone within 20 feet.
And don't worry about losing it, agent. This squirt gun's only $8.