I both corpse-stack by leading demons over corpses and I also dodge back and forth to get Cacos to miss me and gib corpses, in addition to using shotguns to knock enemies back. By now I can predict with a good deal of accuracy where an enemy's corpse will go when I kill it with a shotgun, and that really helps. In addition, I like to weaken enemies with the shotgun, and then deal the final blow with melee so the corpse drops where I want it to. It takes quite a bit of practice, but it's worth it when you master it.
As for the new Ripper, I really like it because then I can increase my damage output by doubling my attack rate. By the time I'm using it, I have enough Brute levels to cancel out it's to-hit minus and still maintain a 98% hit rate. Compared to the Longinus Spear, I got 14d6+30 vs the 8d8+15 that the LS does. The damage increase only becomes more dramatic when you factor in zerking, then it is (14d6+30)x2 for the Ripper, and (8d8+15)x2 for the LS.
For my ridiculously high kill rate, remember that by the mid/late part of the game I had a really fast move speed and I could one-shot everything around me each turn.