Harry was waiting by the door at least. Bob could take down the wards for good, but that wasn't an option right now. Murphy's talisman, currently around his own neck, was their best way of taking down the protections long enough to let people in without worry.
He opened his lips to invite them in, then hesitated, a thought coming to mind as he looked at Jo. He looked in her eyes for a fraction, then averted his gaze and said, steadily, "I'm not inviting you in, Jo. Because if I invite you, I'm letting Molly's power in here. So if you want to come through, you leave that power at the door."
He hadn't thought about this in time to work it out for Murphy, but at the same time, he'd needed her talisman to get inside anyway. So it probably wouldn't have worked in those circumstances. Maybe. It was a clever lie in case she asked.
He shifted his stance, gave Dean a nod, and shrugged. "Worth a shot."