The Enforcer II has a grenade launcher built-in, but it wouldn't be all that fair for us to have -real- grenades.
So, I propose gas - not knockout gas, but a type tear-gas.
It would be fired maybe into an adjacent room, or in the same room...so, the gas would spread, it's maximum intensity and duration determined by whether it was fired indoors or outdoors.
As the gas escapes the canister it's intensity would rise, and every so often all characters in the affected area would make endurance checks. If it fails, they'd run off (flee) in a random direction. Crowd dispersal!
Maybe if a character isn't wearing eye protection, it could possibly (temporarily) lower perception.
I imagine if someone was stuck in a room with a gas and couldn't escape for a long enough while, it could do something else to the guy.
So, that's about the size of it.