Destroy(int)

Destroy a world, destroying all objects contained within it such as all PhysicsBody and attached PhysicsShape and PhysicsJoint. If the object is owned with PhysicsWorld.SetOwner then you must provide the owner key it returned. Failing to do so will return a warning and the world will not be destroyed. You cannot destroy the PhysicsWorld.defaultWorld as it is permanently owned by Unity itself.

public bool Destroy(int ownerKey = 0)

int