It's a hack that works like this.
In a QR game 4-5 people who want to power level go in.
One hacker using weapon spawner(able to equip/drop EVERY weapons) drops a zombie hand(cool, right? xD)
When the host get chosen the humans take the zombie hand they attack the zombies.
Each swing=1 kill. The zombie hands won't affect the other humans.
I've done this and got 10k exp in a 5 round game(10 minutes).