Like others have said, experience is important so do not use your PoCC to kill the ACW, but you can use it to weaken him at the beginning. When I won with a beastfighter it took two disabling potions and attacking to kill him, but without Find Weakness I do not know if you could do that.
If you have not won yet and want an easy finish I would say wand of destruction=AoLS for Khelly because your class power makes D:50 so easy with WoD.
However, if 90 day limit is near then pool sipping is dangerous because you might get doomed a lot and going to Dwarftown every time takes a lot of game time.( unless you have SLBs)
When you DF raid, check the weapons room for one of penetration, as it is slightly, marginally, a tiny bit better against the Ancient Stone Beast than barehanded.
I feel obligated to warn you that the Cat Lord is more powerful than some people make him sound. Read a blessed scroll of magic mapping when you get to his level, because sometimes the stairs are close and you can sneak by him both ways.
Oh, and choose good learner if you do not have it.
That was a lot, but it was stuff that I wish I knew when I first won.( If in fact you have not won yet.)
Closers- GE Wizard, DE Beastfighter, DE Barb
Ultras- DE Barb ULE
OCG- Maybe someday
ADOM projects- Overheat style LP -maybe.