The cestus? The gauntlet? Brass knuckles? Is there a full list of "unarmed but not really" weapons?
Just unarmed strikes and grapples. Nothing else. Feral combat training lets it count for that natural attack.
Would the bonus to grapple checks apply even if the grapple attempt isn't being made with an unarmed strike? For instance, if a Feral Gnasher who has Grab on his Bite attack hits with it and attempts to start a grapple does he get that +2 bonus?
I'll probably stay away from this with my Feral Gnasher since it seems like otherwise I'm likely to get FAQ'd.