No Living Man

[Hot, crispy nice hobbit]

Nobody could come close enough. - Nilpaurion Felagund

That was an understatement: The Westerness swords that the hobbits got were actually daggers found by Ol' Tom the Merry Fellow at the Barrowdowns:

For each of the hobbits he chose a dagger, long, leaf-shaped, and keen, of marvellous workmanship, damasked with serpent-forms in red and gold.

But back to the question of the entire thread, I doubt there are really any other way that the Witchking can be killed, let alone the other eight. Elves were said to have power over things both seen and unseen (See Chapter: Many Meetings), and are thus unafraid to contest the Ringwraiths. But if we are to go into the exact method of how an Elf (say Elrond or Glorfindel) can bring about the demise of the Witchking, we are most likely to be talking about a contest of will-power... hardly of physics. So in that sense, it is pointless to go through the mechanics of how the old ghouls could "die" as long as it dies.

Taken in that sense, anyone with the will-power to spear a Nazgul in the eye can kill it. It is uber-strange however, that nobody have the will-power to kill or even maim one of them for nearly an entire age. We were told of course that the Nazgul are afraid of fire, even though Sauron likes to use it.

Strider laid his hand on his shoulder. 'There is still hope,' he said. 'You are not alone. Let us take this wood that is set ready for the fire as a sign. There is little shelter or defence here, but fire shall serve for both. Sauron can put fire to his evil uses, as he can all things, but these Riders do not love it, and fear those who wield it. Fire is our friend in the wilderness.'

But Gandalf, who is supposed to be a powerhouse of will-power can't even beat them at Weathertop, and presumably with fire:

"Perhaps," said Strider. "For myself, I believe that he was here, and was in danger. There have been scorching flames here; and now the light that we saw three nights ago in the eastern sky comes back to my mind. I guess that he was attacked on this hill-top, but with what result I cannot tell. He is here no longer, and we must now look after ourselves and make our own way to Rivendell, as best as we can."

Granted that Gandalf was tired and outnumbered one to nine, we are still left with the conclusion that the Ringwraiths were completely unscathed for their next uncounter with Aragorn and the hobbits. Big question as to how powerful Gandalf was in comparison with a Dunedain and his halfling cronies... Besides, I am still left speechless with the notion of girl-cum-hobbit willpower combined to "fall" the old geezer of a Nazgul...