We inherited a dog when my brother passed away. Hershey is not potty trained very well so we got her the DoggieLawn. It has specially grown grass that is designed to work perfectly as an indoor dog potty for times when nobody is at home to let her out or it can be kept outside on your balcony as a fresh potty patch for those who don't have big yards.
It comes with a tray and grass you can roll out for the dogs.
The grass is soil less and is easier to lift than sod you might buy at the home improvement store.
My dog was very interested in it.
I think it can be a great potty training tool for all dogs.
It is the ideal potty break station for your pup who might be trapped indoors.