Once again, as was mentioned....
Shrooms can be grown in cow ****. Yes.
But first off all, thats not gross at all. The poo in question is aged. Personally, I prefer horse poo, but thats just me.
For small amounts you can fruit(*trigger mushrooms to form) off BRF cakes(brown rice flour) or whole grains. If you spawn(mix mycelium, the tissue mushrooms come from, think, trees and fruits
) to poo mix it up, and incubate it until you are ready to fruit,
you can use everything from straw, to coo poo, to WORM castings, eww, worm poo, how , um gross ROLF....(or you can mix these together) I am barely scratching the surface here.