Ahh, I don't think that situation really applies to me :3 I don't use phantoms for area clearance, only Jolly Cooperation for boss fights
For some reason I'm having a hell of a time trying to beat
Dancer of the Boreal Valley
, and it seems impossible to summon, be summoned, or actually cross the fog wall as a phantom in that area on the off-chance you do connect to someone.
Even when I eventually manage to spank it myself, my favourite way to farm souls is by co-op... it's SO BORING grinding alone. Much better, I think, to help someone out while getting what you want. Every time I have to black crystal out because I can't cross the damn fog, it's more annoying than if I'd just been killed. At least then I only have myself to blame.