In one sentence, describe what the following article is about:

Like cats, pigs can be litter box trained. However, the box must be big enough so that the pig can turn around fully. That way, the pig will be able to use the bathroom comfortably. For smaller pigs, you can use plastic storage boxes or a regular cat litter box with low sides. For a larger pig, try a plastic kid pool, though you may need to cut an entrance for the pig. Typically, it needs to have shorter sides than one you would use for a cat. Once you have your pig potty trained to a particular spot, it's not going to want to change. Therefore, make sure the place you stick the litter box is where you want it permanently. You may not be able to change it later. Pick someplace convenient for you. For instance, the laundry room might be a good place. Pigs are curious animals, and your pig may try to get under its litter box just to see what's there. Of course, if it does, you'll end up with a big mess. Try to weight the box down or stick it to the floor so your pig can't rummage around under it.  You can simply use a heavier box. You could also glue something heavy to the sides, such as bricks. Alternatively, try using strips of velcro or the like to secure the box to the floor. Clumping litter is not good for pigs because they may decide to eat it, and you can imagine what happens when litter clumps inside a pig. Pine shavings are a great option. Avoid cedar shavings, as pigs cannot tolerate it. You can also use paper pellets or simply layers of newspaper. When you're first training your pig, leave a bit in the litter box to encourage your pig to return there. Pigs like to go where they've gone before, so having a reminder helps.

Summary:
Pick a large enough litter box. Choose a good spot for your litter box. Secure the litter box. Pick pine shavings. Don't clean it completely.