Wouldn't Itachi's Dusk Crow Genjutsu or Ephemeral be more effective for this?Sharingan vs Sharingan Sasuke wins!As long as Naruto never looks directly at the Sharingan he wouldn't be put into a genjutsu,but with the crow genjutsu,if Sasuke looks at Naruto he can be put into a Genjutsu with message from Itachi.I don't think Sasuke has Demonic Illusion: Mirror Heaven and Earth Change,so I don't think he can counter it.Since it was a crow that went into his mouth it might be a safe bet the crow represents Itachi's crow genjutsu.BUT the crow had a Sharingan so your theory would be my second guess.
You must be registered for see links
Dusk Crow Genjutsu-This unknown genjutsu can trap a victim in an illusion with no eye contact, similar to Ephemeral. The genjutsu traps the victim in a torrent of crows, leaving them at the user's mercy.
You must be registered for see links
Ephemeral-Itachi activates this technique by simply pointing at his target. When the technique was used on Naruto Uzumaki, crows flocked from Itachi and turned into shuriken that bombarded him, and then attempted to put him to sleep. When he resisted the sleep command, Naruto then experienced the sensation of his body parts turning into his closest friends who then tortured him psychologically