I use this concept in my Eldar list. I have two WraithFighters and a Seer Council on Bikes to go for Horrify and a Farseer to go for Terrify.
On my blog I often advise that LD is the best stat to attack in 40K, and so it is somewhat surprising that more don't attempt it. many factions dont have ready access to reliable attacks on this but as you rightly point out, the Dark Eldar and of course Eldar do.
Hold out bait to entice the enemy. Feign disorder, and then crush him.
-Sun Tzu, the Art of War