Thanks to all entrants. Many worthy clues.
Receiving 1 vote: darla 6, swarb 20, aristo 31, paul 33
2 votes: amej 8 (plus one like, so bronze on tiebreak), motley 29
3 votes: tyke 26 (silver)
Winner with 5 votes: mattrom 10/17 with the deserving
Fraudster, a piece of work without shame, exposed (9)
Congratulations, mattrom!
Prizes are a bit US-centric, but that's how things are these days, plus the USA has long been at the vanguard of financial chicanery.
Dr. Mesmer (long but interesting):
https://www.youtube.com/watch?v=KQyAnKjD6W4
Snake oil:
https://www.youtube.com/watch?v=LaDsOJATX3A
Salad oil (this was notorious when I was growing up, but is peanuts by modern standards):
https://www.youtube.com/watch?v=48mLzicEHUA
The elephant in the room:
https://www.youtube.com/watch?v=k8TwRmX6zs4
Extra: clip will likely make sense only for US oldsters, but I don't know why this kind of informed protest song seems to have become extinct.
https://www.youtube.com/watch?v=-GjEtv5MXuk