Phorid Flies

[satchellwk]

So, I'm having phorid fly issues.

It all started a month or two ago, I had 2 separate dubia colonies, both of which were overdue for a substrate change. I started a new bin, combining both colonies of roaches and any of my cleaner crew I could pick out of the substrate (I have a mix of dermestid beetles, lesser mealworms, and P. pruinosus isopods). However, I dumped most of the old cardboard paper towel rolls and egg cartons since it was getting old and moldy. Well, I had planned to get some large egg flats for the bin, but upon searching local farmer's co-ops, I was unable to locate any. Therefore, my colony remained for about a week with minimal amounts of surface area or hides. So, when I opened the container, there were quite a few dead individuals, and, since I ended up losing a great deal of my cleaner crew from the substrate change, phorid flies had absolutely taken over. I cleared out what i could and put in some large, vertically stacked pieces of tree bark, so there seemed to be plenty of space now. however, I flies still aren't going away. My cleaner crews look to be reproducing alright, but I don't know when they'll be to the point they were before. Also, the roaches don't seems to be dying at any rate higher than usual, but I still have tones of flies. I've just been taking the bin outside and letting as many fly out as I can about once a week, but they're still breeding. Could they just be breeding in the substrate or something?

TL;DR: I got phorid flies and they don't seem to be going away. Will they eventually just phase out, or should I just dump the whole thing (again) and start with fresh substrate and whatnot?

Any help is greatly appreciated.