Black Ops 2 Zombies Origins Extra Perk Slots Trick + Free Zombie Blood
To get an Extra Free Perk & a Zombie blood you should follow the steps below.
1. Have the staff of ice
2. Fire the ice staff at the 3 burning Carts that are around the Main excavation site ( when you do that the flames will go out )
3. Collect your free zombie blood from near packapunch ( you will hear a noise like a challenge noise)
4. Run around the map looking for a glowing dig site and dig it up
Thats it you have an empty perk bottle to fill.
After about 5 minutes you can get another Zombie blood and look for another dig site they can be anywhere on the map.
NOT SURE IF YOU CAN RELIGHT THE FIRES WITH THE FIRE STAFF but you can get EXTRA PERKS
Video Guide if you like