I use neem oil on my carnivores, so I'll give you my two cents:

Apply in the evening when the sun goes down, I've burned a couple trumpet pitchers by applying in the afternoon.

Water it down a little more than the instructions call for, then work your way up if it's not effective at low doses.

I use the "mist" setting on the sprayer first, wait a few minutes, then hit the plants with the "water gun spray" setting. This'll knock any dead aphids and egg sacks off the plant, and prevent mold or mildew growing on the corpses.