Hey, I have just done this with my guild, after one of the officers thought it would work. Please read on.
Warning: This will require a group from your guild. The more, the faster.
Theory: If you kill one critter, with 10 people in a raid group from your guild. It will count as 10. As everyone gets the credit. So we did some maths. One AoE Spell caster could kill around 2,000 critters in an hour. So if you have 10 people in your group. You get credited for 20,000 critters killed. And the same goes if you have 20 people and so on.
I recorded the whole thing with my guild. And watch how fast we got 12K. Well under and hour if you include travel time. We first tried out the cave in the Plaguelands. And we had an issue with spawns. However, when me and one of my officers tried the penguins, we found. If you killed one, another one will spawn on a different island. So. If you put a group on all 3 of those islands. You get it done 3x the speed. And instant respawns. This is how it was done.
<<<<< WATCH THIS
1 hour = 2,000 (1 person)
2 hour is double of 1.
2 people are = to two hours in 1 hour.
10 people x 2,000 in 1 hour = 20,000
20 people x 2,000 in 1 hour = 40,000
1 kill x 10 people = 10 critter kills.
5 kills x 10 people = 50 critter kills.
5 kills x 20 people = 100.
And so on.
Sorry if that isnít needed. But I think it may help people understand.