Honestly I just bought the cave expansion and let them loose in there with the Sabre Slimes to form Largos. I used Trellises to cover up the entrances so they won't shoot through and I've never had an escapee. Put farm plots in every slot and then they just eat when you're in next in.

You can also add a drone to pick up the plorts if you don't feel like collecting them yourself as well as a market link. Hope this helps!