Orchid growers are starting to use passive hydroponics. It's my understanding that all orchid growers do is use a pot with drainage holes about one inch up the side instead of on the bottom. They fill it with ceramic pebbles and water so that there's a reservoir in the bottom. I would have thought that the roots would rot in the bottom in all that water, but apparently they don't. I don't know *why* they don't rot when sitting in an inch of water, unless I'm missing something.
Anyway, why couldn't this work excellently for Nepenthes? You could use pure perlite or a mix of perlite and ceramic and even limestone or other "exotic" ingredients if your species calls for it. The fact that there's water in the bottom presents a problem (or maybe it doesn't since, for some reason, orchids don't mind and I would have thought they'd be the first plants to rot). Why couldn't you add something impenetrable to roots yet also wicks water up to place in the reservoir? Like that green floral foam, or a dense sponge or something?
The advantage is that you water less frequently, there's maximum oxygen to the roots, and the media is never too wet or dry. Of course there are a few species who prefer it a little drier/more wet, but for the majority of plants, maybe even Cephalotus and Heliamphora (Why not?) I think it would work if we could figure out how to address the reservoir. For some plants that don't mind wet feet, the reservoir wouldn't be a problem. The media is also reusable and won't break down and it's said that this method of growing really increases ambient humidity over normal media. For a media that looks nicer and doesn't float, you could use APS.