A former factory cleaner has denied lacing office coffee with chemicals including Viagra in a bid to “poison” colleagues. Karen Beale had been employed at fire protection product manufacturers Envirograf in Dover for seven years when she was secretly filmed allegedly fiddling with a jar of Nescafe instant granules. Jurors at Canterbury Crown Court heard the camera had been set up in an office after a staff member began to notice several oddities about her cuppa. These included a strange taste, blue and white specks, and a slurry. “Not what you would expect to be in Nescafe,” said prosecutor Ma…