Answer:

quacks

Answer	Crossword Clue
QUACKS	Certain potion peddlers
QUACKS	Charlatans
QUACKS	Duck calls

QUACKS	Charlatans.
QUACKS	Pretenders
QUACKS	They're not to be believed
QUACKS	They treat people badly
QUACKS	Some miracle drug pushers
QUACKS	They need malpractice insurance