About Nunchaku (ヌンチャク;Nunchucks)

The origins of the Nunchaku are not known. Theories and popular notions focus on the idea that it was originally made from modified peasant farmer's tools due to bans of bladed or traditional weapons and lack of materials for more deadly weapons. Perhaps it was a modified horse bridal, the oldest Nunchaku are curved and could be stored and used in/as bridal to disguise it's other purpose. However, the evidence does not support this. Nunchaku are not very practical against other weapons; for instance, an opponent with a sword would have a huge advantage. However, they can be used for grasping, as a blocking device, to strangle, and wielded like a long very flexible stick (or 2 short ones held parallel) for striking. They are really good for showing off (until the wielder hurt himself). They are often wielded in pairs. In entertainment, Nunchaku are good for showing off and much more useful than in real life. For instance, they can often be used in entertainment to block projectiles.

I don't see how this could be accomplished nor have I seen it happen except in more fantastic instances of nunchaku that could somehow retract the chain bit and form a solid staff (often these variants also have 3 sticks instead of 2).

Edit: Also on note of practicality. With skilled user, one could theoretically entangle pole arms by their pole part, or the opponent's hands in case of other weapons, especially in case the opponent is armored and smacking their wrists wouldn't accomplish anything. This would rather indicate an aim for non-lethal/injuring resolution to conflicts. Might make more sense as practice tool for hand-eye coordination and such. But I have nothing to back this up, just some random thoughts on it.