Hi, I have trained all my piggies to use the litter box. The easiest method I have found is to first, take piggy out, empty the litter into a plastic bag so you can get to it later (the used litter, especially the soiled litter from their usual bathroom spot). Then, give their cage a good, thorough scrubbing with a safe for animals cleanser. Concentrate especially on the corners, or areas where they use the bathroom now, the idea is to eliminate the scent of that area totally, so they aren't tempted to continue to use it. I scrub the cage with baking soda, which is a good odor eliminator, or you can use Nature's Miracle, just rinse both out well. After cage is clean and dry, put your usual litter in. Then, get the litter box, scoop some fresh litter in, BUT, also scoop a bit of the soiled poo and pee litter from their old spot in the little box. You can even place it (the box) in the same corner they used to use. That's it, 9 out of 10 times they will begin using the box immediately. If you let it get too dirty though, they'll stop using it until it's cleaned. It's very much worth it, I've found I need to clean the cage less often. Good luck!