I dont really see any point, if all you want is just look like a Goblin, while people in Druid Groove, Tollhouse, Waukeen's Rest, and potentialy Baldur's Gate ... are talking to you just as if you were anyone else.
(Aka. the way we have it now with Drow.)
Then ... i would say, such half-baked implementation is work for some beginner moder. :-/
I would settle for this, honestly.
Of course it's not the ideal way to go (Everyone is distrustful of Drow and Goblins, obviously), but Faerun is more of a "forgiving" place now. Half-Orcs aren't 100% distrusted, and the Drow/Goblin walking around is probably a lot more tolerable when they're in a group with others (ie. Shadowheart, Minsc, Jaheira, etc).
I would be more than happy just going that route.