I would recommend greased so you can dump full clips faster, or incendiary to buff the chance of flame stacks on each hit. The only goal is to add as many fire stacks to the hull armor as possible as quickly as possible by aiming directly for it. The AOE fire chance, and the fact that the gun is wildly inaccurate, will insure that there are some fires on components other than the hull. ~1/3 chance of a fire stack on direct hit, ~1/4 chance of fire stack on AOE - not bad. The engineer(s) will then have the choice of running around to maintain the ship's components or babysitting the hull, which should all be in flames and taking direct/AOE/fire damage constantly. Even if they babysit hull, you should earn some component disables. Since the banshee is explosive/explosive, albeit low damage, once the hull inevitably goes down, you will get some health damage in there. Lather, rinse, repeat as desired.
That's the most effective way I've seen it used, but I'm actually in the "not enough experience with it" boat as well, so I'm looking forward to getting some other player's perspectives.