I leave my Nepenthes densiflora pitchers alone during winter, but come summer when it really gets hot and dry here, I spritz the pitchers.
Right now my Nepenthes behaves differently, seems to enjoy watering from below, making it stand in water. If I have rain water, I use rain water, if none, then I use distilled water, not our tap water.
Oh, if I do catch an errant spider indoors, I give it some..loves it!
Here is mine: