There are times in our lives when we have an illness or an accident for which would give anything if there were a quick cure. For centuries, some have taken advantage of this need and have tried to sell the public on a gizmo guaranteed to cure a malady.
In reality this practice continues today - just spend some time watching late-night television. The medical profession of the past was not as extensive or monitored as it is today, so gullible folks could readily be sold a ‘cure’ with few consequences if it didn’t work.
The ‘truth in advertising’ movement was in its infancy, so few people were going to stop an electric treatment ad touting the cure for ‘pain, weakness and nerve vital derangements’ from a layman not a doctor.
There are collectors who enjoy the old advertisements for these quack gadgets as much as the gadgets themselves and are willing to pay a handsome price for both.