I don't know if you could even do it with a goose but my dad potty trained a cockatoo. She had a potty perch that she would go to and go potty. Also she did 'on demand' potty training. So when she was out she would only potty when my dad held her out and said the magic word "squirt" Of course geese are a little different but they are smart so maybe it could be possible to potty train a goose. I wouldn't keep a goose indoors but I certainly would keep one on the front yard if I could keep it from pooping all over the place and on the porch.