Most students of the law will be familiar with the infamous "Carbolic Smoke ball case" as it forms a legal precedence of some significance.
However, for this topic its relevance is that in the 19th century this product was advertised as a cure all. You placed this bomb like contraption in the middle of the room, lit a fuse and it emitted carbolic fumes which - it was claimed - cured everything from toothace to ingrowing toe nails!
The gullibility of some folk is incredible.
I once prosecuted a case for a device which "....transformed your deadly dull black and white television into amazing colour". It was a bit of sticky plastic which you stuck onto the screen of your TV. the top third was blue, the middle third was red and the lower third was green. i just showed the court a TV sequence of a dentist operating, through this marvellous product and achieved an immediate conviction.
One week later I got letters from the public telling me it was a "marvellous invention"!
I rest my case your honour!
Roger in France