People should keep experimenting with Neps like you have been. A Nep may suffer a bit or even die, but, you could really get a good growing method and get many more people to give them a try.
For me? I grow and cultivate two very successful colonies of Fruit Flies. Each time they mate the collection gets LARGER. It has this crap at the bottom and straw, the flies just love it in there. I was scared of them at first, but now I think they're cute. Unfortunately, the walls had become FULL of them, and I was afraid of over population, so I had to feed a ton to plants, and some I had smashed along the rim, unintentionally and sometimes intentionally (It was a lot of fun, but then I felt a little bad, but then remembered it was for the "Good of the "People". They've made Fab. Heliamphora, Dionaea (smaller plants, and a couple of fruit flies, though, since you can hardly get one into a trap since they are hyper little buggers, I use the maggots, it's much easier as they don't move). My Cephs seem to like them, one of the pitchers gorged on about 10 fruit flies, and another about 7. This kicked growth up A LOT. When I got it a few weeks ago, it suffered minimal root disturbance (My Heliamphora got most of it >.<) and it recovered quickly, only the tiny pitchers dying. The largest pitcher is almost done developing! Hurray!
My N. ventricosa is producing multiple "hooked" leaves with fat tendrils at the ends, a sign of pitchers. Fruit flies would make good food, eh? Though, some tend to escape. You usually see them found dead later on your Pings or crawling on your pots. It's kind of cute. Or drowning in your water trays. They can survive quite a long time in pitcher fluids. One fruit fly was a fighter, I put him on my Ceph and he naturally fell in and he was still fighting AN HOUR LATER. I contemplated taking him out, but he must've been a beefy fella, so he would provide good nutrients. The fruit flies tend to get skinnier and turn pitch white/pale. The way you can see them is their eyes are still the bright red.
By the way, my Heliamphora is an EXTREMELY RARE SPECIES. Nobody has it but me. I've cultivated it and named it Heliamphora 'Minor' var. Brown. All you have to do is grow it bad!
Seriously... it could be dead O_O. While I was putting it near better light, I found a pesky fruit fly. Ironic!