Heres the best way to boost if you have 2 PS3's:
- Use the dummy account as the host and use the settings from the OP.
- I highly recommend a turbo controller to turbo

+

, otherwise it will be really stressful..
- As soon as the game starts run towards the "Damage Boost" and avoid the shotgun by running to the right or left of it. Grab the Damage Boost and quickly run towards the enemy spawn and pickup the machine gun, do NOT kill the the enemy yet and instead start running up the stairs. Once you reach the top turn around and shoot him and he will spawn at the farming zone.
Now simply grab the grenade launcher and go to town! Since you have the Damage Boost you will get 6 kills back to back and when the grenades run out get a quick kill with the machine gun and after that more grenades will spawn, get them and finish the round. (You will have 16 points after the machine gun kill, the second batch of grenade ammo is enough to end the round.) If done properly you can get a win every 35-40 seconds and its hassle free!
I made a video.