Not sure, really. So far, I've only got two recipes, and both require things I can get at the poison vendor. As soon as I get more advanced recipes, I'll start posting about em.
By the way, I noticed something about the poisons in the item screen. It lists at the top: "classes:rogue." Not sure if that means that only rogues can apply the poisons or not. If that is the case, then you'll have to be with a rogue who can actually apply the poison for you. Not sure about this yet. I'll need to test it out ingame.
Update: Tried poisoning Meifftor's weapon in-game... apparently, poisons can only be used by rogues on their OWN weapons, not others. Blizzard really doesn't want rogues to poison the weapons of others for some reason...
Sorry to have misled you. I suppose you should all stick to sharpening stones, heheh.
Will still be requesting poison reagents on here, however.