snake oil Snake oil - Wikipedia
“a snake oil salesman is someone who knowingly sells fraudulent goods or who is themselves a fraud, quack, or charlatan.”—Wikipedia
I recently found that Donald Trump can be properly described as a snake-oil salesman.
Donald Trump: The snake-oil salesman who hijacked a party Donald Trump: The snake-oil salesman who hijacked a party – The Irish Times via @IrishTimesWorld
The irony for the party Trump has acquired in a hostile takeover is that he is not a conservative or even a Republican. He is in the business of snake oil. He has hijacked the conservative movement’s “us versus them” division of the world and has appealed to blue-collar Republicans and former Democrats whose lives have been destroyed by the movement’s economic platform. http://www.irishtimes.com/news/world/us/donald-trump-the-snake-oil-salesman-who-hijacked-a-party-1.2731826
Snake-oil, sounds like poison to me.
There used to be toad-oil salesmen(ガマの油売り) in Japan.
The oil was regarded as a “panacea”, but it was acknowledged that it did not have any effect on lovesickness and bald heads.
"四六のガマは己の容貌を今業平（在原業平のような美形）だと信じているが、周囲に鏡を張った箱に入れれば自らの醜悪さに驚き、脂汗を流すという。この汗を集め、一定期日のあいだ煮つめてできたものが「ガマの油」である、という。"(Wikipedea)