The Dan Bong is a monk weapon, which means no Exotic Proficiency necessary and it'll use the monk's unarmed damage regardless.
While it is possible that one could enchant a Dan Bong, it's not likely of much benefit.
In practical use, the Dan Bong does not inhibit grappling maneuvers, instead enhancing your hand with additional bony protrusions with which to apply pressure. This doesn't cause any real damage, but a nerve-fulcrum to gain leverage on your foe, and therefore a RAI +2 bonus to grapple.
Do note that other monk weapons add bonuses to other maneuvers: nunchaku/sai grant +2 to disarm attempts, and kama can be used for trip.
