Hmm, perhaps I should use less water the next time then. It was slightly less thick than that.Once the cups cool (as you should mix them with hot water) the media shouldn't move. I like to think of it like the DQ Blizzard (flip it upside down and it shouldn't drip down).
Fantastic post, total light bulb moment for me, never considered the double stick tape route, been using vaseline like a total noob.IMHO, regardless on the media. I poor 3/4 cup boiling DI water into 1/2 cup media. I do not stir, I let it sit overnight to cool to room temp. I then sprinkle a tiny(1/8 tsp) amount of cinnamon on top, twist excelsior into it. I then spread/pull the excelsior from the middle to the outer edges of the cups(limits the magots reaching the very top). This has worked for me for a few years now. I always have a few dead flies end up on the bottom. I have read all the mixing instructions but I always boil the DI water. This seems to make me the best batches. I will say josh's frogs media is very good! Best mod I have done is having a bed of Diotomatos earth in a tub. I put the cultures on that. I also run 3m double sided tape around the upper edge of the tub to catch mites. I have not had a collapsed culture yet. But i am vigilant with wiping the outside of the cultures down to remove any mits that find their way in!
OK long rant. Hope my 2 cents is helpful.