Ceramic balls in hub bearings???

Hi

I have purchases 18 ceramic balls for my Dura Ace rear hub. Not because of the reduced friction or weight, but because my hub shows clear signs of wear and I was told that the ceramic balls are so hard that they can cut a knew "thread". If this is indeed the case it saves me from buying a knew hub which would have been way more expensive than these balls.
I was also told that ceramic balls only need oil and not grease like normal steel ballbearings. However I would think that using normal oil would mean that I have to maintain the hub much more often than with grease?? For these reason I'm using grease as normal(and thereby losing the small advantige of reduced friction).
The finally get to my question. Have any of you had any experience on the subject? Grease or oil? Can they indeed prolong hub-life?

Thx