I don’t think Regina would need to brainwash Belle into hating Gold. What he did to her was enough for her to not go back to him. I wouldn’t go back to a guy who acted like. He is too erratic and completely flipped out and even though he felt sorry about it afterwards i really think he would do it again. I mean look at what he did to Belle’s father.
Hmm, it depends on how you see it. Belle’s final words to Rumpel seemed to be that of regret and longing. She tried to convince Rumpel to let her stay and give her another chance. So, she seemed to be still in love with him. And if that’s the case, then Regina will need to brainwash her.