Speaking to ABC's "Good Morning America" in an interview broadcast Thursday, O'Donnell agreed with the suggestion that the ad only brought fresh attention to the issue surrounding her past statements as a TV commentator.
"I haven't publicly stated this, and I don't know if I'll get in trouble for saying that, but our intention was to kill it, and that's not what happened," she said in the interview.
O'Donnell's comments about witchcraft were made over a decade ago during a taping of comedian Bill Maher's "Politically Incorrect" TV show.
"I dabbled into witchcraft. I never joined a coven," she said on the video, a clip of which hit the Internet just days after she stunned longtime congressman Mike Castle in the GOP primary in her third bid for Senate.
O'Donnell also defended comments made during a recent debate with Democratic rival Chris Coons in which she challenged him to show where the Constitution requires separation of church and state. The words calling for separation don't actually appear in the Constitution, she told ABC.
In a lighthearted exchange near the end of the interview, O'Donnell was asked what costume she would wear for Halloween. "I certainly am not going to be a witch," she said. She joked that she may dress up as Dorothy, an apparent reference to the heroine of "The Wizard of Oz" story.
"Kill the witch," she said laughing.