Seduce is extremely reliable for me (70 lock), I use it constantly in heroics. The key is setting a mini triangle of aggro, searing pain + CoS the mob to avoid resists, then seduce on the run.

The rough part is you can't recast seduce 1.4 seconds from the expiry like you could with polymorph. It never resists for me though (almost never), so I wind up a fear when its expiring, then recast and it stops the mob in its tracks. Works everytime for me. If the mob resists, throw curse of recklessness on it, then juggle back to shadow fast while reseducing. Sounds complicated, but with CoS up they just don't resist anyways. I play a mage and a lock, seduce CC is just as easy for me as polymorph.