Paintball gun
From Tardis Wiki, the free Doctor Who reference
Paintball guns were handheld "weapons" that fired small, non-injuring paintballs as projectiles, for use in the sport of paintball.
Wilf used the weapon to attempt to blind a Dalek by shooting it in the eye stalk. However, the effort was useless asthe Dalek vaporised the paint, clearing its vision again. (DW: The Stolen Earth)