Question
I was just wondering, old nepenthes leaves seem to go quite woody when they die off. could I re-use these mixed into carnivorous plant soil to perhaps help with drainage, For nepenthes mostly. Or might it cause disease?

Answer
In horticulture, there's a notion that the best compost for any plant is decomposed plant parts of that very plant.  This makes sense when you consider a plant's life in nature.  We toyed with the idea of using Sarracenia pitchers in our Sarracenia soil mix, but we never actually carried it out.  

I can't say for certain what would happen if you used old Nepenthes stems and leaves as a media constituent.  My hunch is that you can get away with it if you make sure that water drains freely through the soil and pot.  In the wild, Nepenthes leaves and stems will fall off and decompose in the soil beneath.  However, there is usually heavy rainfall that washes away decompose material and nutrients.  I also suppose you can argue that this is no different than using bark or wood chips.

It's definitely worth trying.  As long as water flows freely through the soil and pot, old stems and leaves would make a fine media constituent.  

Good growing!
Jacob Farin