I've raised several goats and lambs in the house! They are so much fun!
Try using puppy pads. I would throw one under them when they started to pee. You won't have to have as good of aim as you do with a can!
Also, may I suggest a whisk broom and dustpan!
The very first one I raised in the house was such a pet. She walked on a leash and would jump up into any vehicle if the door was open. She liked going for rides, just like a dog.