Interesting responses all. I don't ash in my plants (I rarely even smoke ciggarettes anymore) but I was just thinking about it cos I was visiting my uncle and he still does that. He only grows one CP (my N. Ventrata came from him 6+ years ago) but has a house full of other stuff - mainly he's a philodendron phreak.
I have heard of people putting coffee grounds on their plants so Green tea wouldn't be too crazy of an idea. I just read a section in my lily book about making "manure tea" but I don't think that would go over well inside on houseplants!