You still technically can’t.
FAQ is NOT errata, and is overwritten whenever it comes into conflict with the rules, especially with the core rulebooks. It explicitly states in the monk description that a monk CANNOT TWF with his unarmed strike.
If you were referring to errata, which is basically a retroactive change in the text, then yes he could.
Where does it say it? I just checked the SRD and it doesn’t say that at all. In fact, the only mention of “off-hand” notes that a monk gets full strength damage on all unarmed strikes.
This means that a monk may even make unarmed strikes with her hands full. There is no such thing as an off-hand attack for a monk striking unarmed. A monk may thus apply her full Strength bonus on damage rolls for all her unarmed strikes.
Note that TWF attack penalties still apply, however.
EDIT: Note also that by RAW Biff’s post is wrong too. Any unarmed strike counts as a primary hand with regards to Strength bonus to damage. TWF only notes that there is a penalty to attack. The Strength bonus to damage entry is overruled by the monk class entry.
A TWF monk gets strength bonus to damage for all unarmed attacks, at least by RAW.
