I had better luck just sabering them to death, but that was because my light side characters tend to be melee focused and dark siders are Force users. Most of the really nice offensive powers are dark side anyway, so the discount on the force points helps. I came back as a Sith in a later game and filled the whole room before killing them all with lightning. Eh, it's really not that important, I guess--the game was somewhat easier than the first KOTOR, I thought.