Though magic was mainly used to protect or heal, the Egyptian state also practised destructive magic. The names of foreign enemies and Egyptian traitors were inscribed on clay pots, tablets, or figurines of bound prisoners. These objects were then burned, broken, or buried in cemeteries in the belief that this would weaken or destroy the enemy.

In major temples, priests and priestesses performed a ceremony to curse enemies of the divine order, such as the chaos serpent Apophis - who was eternally at war with the creator sun god. Images of Apophis were drawn on papyrus or modelled in wax, and these images were spat on, trampled, stabbed and burned. Anything that remained was dissolved in buckets of urine. The fiercest gods and goddesses of the Egyptian pantheon were summoned to fight with, and destroy, every part of Apophis, including his soul (ba) and his heka. Human enemies of the kings of Egypt could also be cursed during this ceremony.

Magical figurines were thought to be more effective if they incorporated something from the intended victim, such as hair, nail-clippings or bodily fluids.
This kind of magic was turned against King Ramesses III by a group of priests, courtiers and harem ladies. These conspirators got hold of a book of destructive magic from the royal library, and used it to make potions, written spells and wax figurines with which to harm the king and his bodyguards. Magical figurines were thought to be more effective if they incorporated something from the intended victim, such as hair, nail-clippings or bodily fluids. The treacherous harem ladies would have been able to obtain such substances but the plot seems to have failed. The conspirators were tried for sorcery and condemned to death.

http://www.bbc.co.uk/history/ancient/egyptians/magic_05.shtml