Head up the tunnel that leads to Rathe Chambers. As the tunnels open up into the catapult area you see a couple of campfires with bunches of mobs around them. The first two each have a messcook. The 4 times I spawned this named he came from the northern of the 2 campfires. That doesn't mean that the southern cook isn't also a PHer but I never saw Slaukk spawn there.
Here's the best way to camp Slaukk. Just north of the north campfire there is a wall to the east. Set up at the spot just before the catapault, loc is approx pos 2680 neg 895. No wanderer there. Pull the messcooks (you will need a good splitter or superb crowd control) and keep killing them till Slaukk spawns. Repop timer is 15 minutes. Lotsa add potential so if you can handle them this is also an excellent XP camp.
I suggest keeping the gob behind the catapult dead. He seems to have unusual assist-aggro. He added to some of my fights but late, which means he wasn't within aggro range on the pull and the initial engagement, but then he added later, bringing friends with him. The gobs here seem to have that tendency, from what I've seen. In any case I keep dead any gob within LOS of any place I'm going to fight. Just to be safe.
Slaukk drops the apron as his common and the melee ring as his rare. In my 4 kills we got 3 aprons and 1 ring.
The named isn't very tough. If you can handle zone trash COMFORTABLY you can handle the named. I suggest fighting close to the wall since it's easy to get adds in this crowded location.
Tip on pulling: you can climb up the walls very high, with lev on. This means you can pull by casting from way ABOVE, thereby not getting pounded while casting.