I wouldn't have thought so...

Thats what carnivorous plants eat - why would you want to kill them?

Well, since greenflies don't get around much, most escape the "maw". Probably the safest thing to use is a water soluble extract of the Neem tree seed, since the oil type is likely to damage the leaves of most species. It is slow acting, since it doesn't kill adult aphids, but instead keeps the babies from growing up. Insecticidal soap is possible, but many species of carnivorous plants are sensitive to the potash in it. I haven't had a chance to try pyrethrin or pyrethroids on carnivorous plants--they are a cautious possibility.