All the eluder skills work on one mob, you have to target the mob and use the skill on it. I have tried this in the past and it worked, I threw a stone at a wolf, then used Beastkin Eluder. It went from claimed to unclaimed. I kept throwing stones at it but it wouldn't aggro or go claimed.

I personally would prefer a buff that gave you the eluder ability for a short duration rather than against a single mob.