Charles Spurgeon Commentary 2 Chronicles 33:6

"He also made his children to pass through the fire in the valley of the son of Hinnom; and he practised augury, and used enchantments, and practised sorcery, and dealt with them that had familiar spirits, and with wizards: he wrought much evil in the sight of Jehovah, to provoke him to anger." — 2 Chronicles 33:6 (ASV)

Also he observed times, and used enchantments, and used witchcraft, and dealt with a familiar spirit, and with wizards: he wrought much evil in the sight of the LORD, to provoke him to anger.

You cannot imagine, I think, a worse character than this Manasseh was. He seems to have raked the foulest gutters of superstition to find all manner of abominations. Like false-hearted Saul, he had dealings with a familiar spirit; he had entered into a covenant with Satan himself and made a league with hell, and yet, marvel of grace! this very Manasseh was saved, and is now singing the new song before the throne of God in glory.

And he caused his children to pass through the fire in the valley of the son of Hinnom: also he observed times, and used enchantments, and used witchcraft, and dealt with a familiar spirit, and with wizards:

All of this is imitated today by certain persons who try to break through the veil that separates us from the spiritual world.

Manasseh did this on a large scale.