Cooking them on low for a longer time is a great way to combat drying out, which is more likely to happen if you cook them at a higher temperature for shorter. You may also want to dredge them in flour and seasonings, which can help keep moisture in. The mushroom soup in these crock pot smothered pork chops also prevent drying out, but if you still find your pork chops are dry, you can try adding a splash of your broth of choice.