Ever think about using wild brett? I see little pellicles pop up every time I forget to clean up a spill. It has happened at the past three places I have lived, which to me says that brett is absolutely everywhere.
I had wild brett get into a dry stout I made once. We drank it before it changed the flavor profile at all, but it was kinda neat...I have a habit of never finishing the last sip of my beer. Every time I left a glass out, a pellicle would form. Sometimes in a matter of minutes. You could see the surface of the beer start to lace together. I kind of wish I had saved some to try brewing with.