This works solo, but should be adaptable for MP zombies.

Solo: Get Claymores. Drop them by Juggernogg so that they are all aimed at the center of that tiny alcove where Juggernogg is. When the ZT comes, go into the back-center of that alcove and he will walk into this minefield and die instantly, usually giving you Bonfire Sale and Max Ammo. I did this on every round that he came including round 32 (I got to 34) and it still took him right out.

Remember to drop your Claymores right away as a round starts so that Max Ammos will give you 2 more.

MP Zombies: I assume he may take more damage in MP. In this case, each player should find a spot that they feel comfortable in. Some ideas: ends of Starting Room hallways, unused corners of the Laboratory, the top Elevator. Then, as he come for each player, he will surely take enough damage.

Happy "FIVE"ing.