I've been doing this here and there. I tried doing different seeds on different mobs but it just wasted time. Now, I just sic the pets, cast SoC on the first mob then immediately cast SoC on another mob that I hope won't die. Sometimes it works. If you have a pack of mobs with one hard mob in the middle, just drop Corruption on the hard one, then stack 8 SoC's on him. It'll kill off all the rest.

FYI, SoC only does DoT damage to the mob it is on. The Explosion only hits other mobs around him. Also, the SoC won't go off until the target receives 1200 damage.