Ok, to clear up some confusion I'm posting what I did to use this quest and raise my KOS freeport faction up to amiably in a few hours. This is the Inert Potion quest in Erudin.
This method was described in a different post, but I changed a few things about it.
First off, yes Toresian says something about someone in the temple of Marr. Don't worry about it, I didn't. When you say to him "I study enchantment" a version of Slansin will spawn in the store near the bank. There are TWO versions of him. The more common one (at least for me) is a human model that conned light blue to my 70 pally. When I gave him a potion, I got negative faction hits with the guards and he would despawn. I ended up doing this for about 8-9 times getting the wrong one to spawn. Finally though, an Erudite male version of him spawned, and he had an enchanter pet. This is the version you want.
I taunted Slansin, and when he aggroed I took him up next to Toresian. None of the guards or other NPC's seemed to care. When he was right next to Toresian, I rooted him. His pet attacked and I rooted it a bit away from Slansin. This is where it would be helpful to have a friend along to hail Slansin over and over to keep him from walking away. Luckily my computer zones rather quickly, so I was able to camp out and get back in before root broke.
I had a hotkey set up with the first line being "/tar Toresian" and the second line being "/say I wish to assist Toresian". Here is where I found an interesting trick to speed things up. The inert potions he gives you are lore, however if something is sitting in an open trade window, you can request another one! My pattern was simple:
I would get a potion by using my hotkey. When I had it I would open a trade window with Slansin. This is where I would usually hail Slansin to keep him from wandering off. Then I would hit my hotkey again and spam it until I got another potion while the trade window was still open. Each time I would get a potion, I would drop it in another slot on the trade window. This way I was getting four faction hits per turn-in!
This still took me a few hours to go from max KoS to amiable. Don't be suprised if after doing this for a few hours and you find they still want to kill you. From what I've seen, the difference between max KOS and the next step up, threateningly, is HUGE. But once you get out of the "scowling, ready to attack" faction tier, it goes really quickly.
Another thought, since it happened to me. I accidently killed his pet once while running him up to Toresian. When I had him right next to Toresian and was doing turn-ins, he eventually summoned another pet that was right in the way of doing turn-ins, no matter what angle I tried. I didn't really want to root him and camp all over again. I found that if I taunted just the pet, but never actually hit him, the pet would attack but Slansin would still do the quest. I did this and had the pet to my back, hitting me once in a while for 1. Low lvl peeps might not be able to pull that off, but at 70 it was a cakewalk.
Also, if Toresian will not give the quest, kill the low lvl necro that spawns near the docks in Toxx forest. Collect his bones for some free guard faction as well. I did this for an hour or so and was then amiable to Toresian (I started at dubiously)
