WE SHALL CHOAK THEIR RIVERS WITH OUR DEAD!!
That is where you go wrong. The proper way is to:
Choke their rivers with their dead. Unless you are Kzin of course.
Na. I've got plans for their dead. As for our dead, I kinda screwed them up too much when they were alive, so they're of no use to me dead, so we either give them funerals, or choke others rivers with our dead.
Either way, I've got plans for their dead.