In 19thC Cornwall, just mentioning that a victim would go to the conjurer of Sithney was enough for a frightened thief to return the money to its rightful owner when he heard of it.

'About a fortnight since,' states the Cornwall Gazette, 20th February 1802, 'there was stolen from the house of John Hockin, a labourer of the parish of Sithney, a small bag, containing cash in the amount of about £10, the property of his son. Suspicion having fallen on two or three of the neighbours, a warrant was procured and their houses searched, but to no effect. The young man, however, being unwilling to give up his money without some further research, resolved last Saturday to go to the conjurer and declared his intention to some of the neighbors of going the next morning. Superstition effected what honesty could not; the terrified thief, in the course of the night, brought back six guineas (perhaps all that was left), and dropped it in at the door of the house whence it had been taken, to the joy of the family, who found it in the morning.'

Sithney is a nearby village to where my great–grandfather lived and worked, so he may have heard of the conjurer of Sithney.