Growing Hoyas the way that I do is a lot of work!  The pictures below show the tray that I keep in my small grow tents for added humidity.  I think that I may have created some Frankenstein type, new-life form in this primordial ooze.  It took a shop vac, vinegar, bleach, scrub brushes, a lot of elbow grease, and time to clean all of this out.