A year or so ago, there was an AMA with Miles in the ants and antkeeping server, and I remember him saying that if you manually put ant colony's trash in a certain area enough, they'll start to do that themselves. I tried that with my Lasius neoniger colony a few weeks ago, and it actually worked(which surprised me). Mine also put trash on sugar water(it'd probably work with normal water too), so you could probably utilize this as a way to make cleaning up easier. It doesn't work with larger pieces of trash though. I don't have a before picture, but this is what my Lasius neoniger outworld looks like now.
In green is the area where their trash used to be, blue is where I put trash in and they moved their trash in that little dish, orange is where their sugar water used to be.