rawhide
Rawhide can be very tricky! And only to be given under supervision. It can cause diahhrea if eaten, and can also cause blockage in the intestinal tract and is a choking hazard, especially in chi's! Also, rawhide gets ooey and gooey and can be a breeding ground for bacteria.
I would recommend greenies or compressed rawhide which comes in flakes, so theres no choking hazard and large quantities cannot be bitten off at one time. Cow knuckles and pigs ears are great and dogs love them!
One more thing, you could get your chi a Kong. Fill the inside up with either peanut butter or yogurt and freeze it. Your chi will spend hours chewing at it, adn its a great, healthy treat to boot!