How exciting! Congrats on your new babies.
We use the Potty Training Puppy Apartment too. We love it! It has been a wonderful experience! It came with a instructional dvd that I went by. Is this the same thing you are talking about? We ordered ours from Modernpuppies.com. I let Katie Scarlett get used to that before I started introducing outside potty too. She rarely will poo outside unless we are on a long walk, but she will pee pee out there. But sometimes she will hold it and use the PTPA as soon as she comes in. She likes it better I think. As for using it for 2 at the same time, I am not sure about that part.
I'm not sure about the getting along part. I only have 1 furbaby and she is my first.
Good luck to ya!
