What I did in FTM 2012 was go to reports and publish a "Kinship Report" (I selected my daughter to cover both my line and her father's line).
In the options to the right, I selected:
Show Unrelated Individuals
Show All Relationships
Sort Individuals By Kinship
Most of the "unrelated" will show up at near the end of the report.
I don't see an easy way to remove those people, but at least it IDs them and I can go from there.