If this plant has already hermed then it is definately not a candidate for feminized seeding! The seeds will be double reenforced with an easy-to-herm trait, and many will be herm from birth.. Feminized seeds are created from plants that resist herming out much more than typical plants, but they can still be forced to herm under certain extreme stresses.. Good feminized seeds are a real chore, requiring real experience to produce, and IMO, they're still sketchy..
Really, I agree with the opinions above.. Kill it and dispose of it safely.. Hermies may have a place in the porn industry, but they shouldn't be tolerated in this activity..