Hey mate.
Another thing you may want to do is try to whittle the health down of as many of them as you possibly can.
Bloodsplosion works as a multiplier of overkill damage, and due to that, it helps to heighten the effects of the overkill.
Use weaker slag grenades so that you can control the damage being done to them, then slice them up within an inch of their lives.
I wouldn’t spend too much time actively bothering with getting to that 100 stack, if you are whittling them down with a Moxxi weapon, you should get there naturally. (You’ll easily fire more than 100 consecutive shots on the Spiderants).