Fastest / Easiest Way to Kill D Clone?

I have heard of a trick with the chaos sanctuary, but last time I went and popped the seals I couldn't find Diablo - maybe I am not doing it right.

I don't have a character that can consistently kill diablo clone quickly. I have done it on my blizz sorc but kiting is a pain and it takes time. I just tried on my hammerdin - hammers did negligible damage so I spec'd him for smite. I don't have smiter gear though, so I threw on Rattlecage for crushing blow and bought a life tap wand. I nuke Diablo down to ~10% fast but then he stays there and regenerates all of my damage. I have a weapon or two with prevent monster heal but it is inconsistent to try and land a hit with that and then swap back to my setup without dying.

Any tips? It seems really easy it's just frustrating that I'm struggling even with everything at my disposal.