A thorough physical cleaning and delousing is absolutely necessary before the Bidens move in. But I think some thorough spiritual cleansing is necessary as well. Perhaps a good and prayerful smudging with sage and the sprinkling of holy water. Different religions have different rituals for clearing a place from evil, and perhaps all of them can be carried out in an interfaith service.
Zackly what I was thinking. Bring in an exorcist too.