Sorry to hear about your VFTs, now we know they don't fly!
(just cheering your up). No need rooting hormones in my opinion. Healthy leaves are the best for leaf cuttings, I have not had good sucess with trying leaves that has started to have black tips.
You might want to cut off the traps on the leaf cuttings. Also I suggest (like others) very wet or moist conditions, and good sunlight (no need direct, but good sunlight), I have never been sucessful with artificial light or low light cuttings myself.
Did you mean you intentionally split the rhizome in half? Well if you have 2 rhizomes now with a few leaves and roots each half, then you might end up with two plants in the future.
Good luck!
TTFN
Arvin