Yeah, I usually just whisper once and it goes something like, "Will you please spawn a few Great Spiders for me?" <---- or something like that. Then afterwards I also whisper them and tell them thanks.
They have yet to fail spawning what I asked for right after I ask them nicely.
And one time, I whispered back "thank you, even though I did not get the kill shot." next thing I know, 4 more spawned.
