great till like ringworld novel they get loose, in ringworld is was metal but eating the insultive plastic off of wires could set our civilization back to the iceage. So basically we'd need to drog the plastic into a container of glass and have it so the bacteria are killed it they near the opening with uv radiation or something. This is playing with fire in the long run. You know some fool would try to set them loose in the ocean but they come ashore and start eating anything like powerlines or storm windows and just overrun everything. Also that seal container would have to be destroyed with the bacteria in it since you'd fill it with the waste and then run out of room. It's like useless if you cannot control the bacteria completely as in they cannot move or reproduce so it's an accident waiting to happen.