He did use YOU, and apparently YOU need glasses.
You misread what Paul said:
“The word is near you, in your mouth and in your heart” that is, the word of faith which we preach: that if you confess with your mouth the Lord Jesus and believe in your heart that God has raised Him from the dead, you will be saved" (Ro.10:8-9).
Paul is not telling the people to confess the Lord Jesus at all. Instead he reminds them the word of faith that is being preached by he and the others.
You are reading into that verse something which is never said. Where do we see Paul telling these people that they must confess with their mouth the Lord Jesus? He doesn't. He is merely reminding the readers of what he and others preach.
Also, according to you at the eighth and ninth verses of the 10th chapter Paul is addressing the unbelievers then later in the same chapter He is not addressing them at all:
"How then shall they call on him in whom they have not believed? and how shall they believe in him of whom they have not heard? and how shall they hear without a preacher?" (Ro.10:14).
You do not even give an explanation as to why Paul would do such a strange thing. And of course you just ignored the fact that Paul does not say a thing about his writing to both believers and unbelievers:
"To all that be in Rome, beloved of God, called saints: Grace to you and peace from God our Father, and the Lord Jesus Christ" (Ro.1:7).
If his epistles were addressed to unbelievers also, why didn't he mention that?