Sustainable medium

[ewn4]

Hello All. I recently re-potted my first orchid in a commercially-bought bark mixture, but the materials did get me thinking... In general I've been trying to increase my level of environmental sustainability in pretty much every arena.

After lots of research into growing media, including water culture, semi-hydro, coconut-based varieties, etc...I'm left with one burning question. Why can't I just grow my phal using whatever shedding bark I find in my local park mixed with some stones from the yard, some larger sticks or pieces of mulch, and a couple leaves? Let's assume it's all sterilized.

Why the mix? I've spent hours trying to find someone who has done this, but the internet is full of those who seek the perfect highly-specialized media, not the most sustainable. So, can what I propose be done successfully?