A hundred years ago the travelling "snake oil" salesman would open up his stall in the market square of a small town and begin plying his wares.
"Roll up! Roll up! Medicines to ease your aches and restore and rejuvenate. Patented Tincture of Tarantula, Excellent Extract Of Electric Eel, Omnipotent Ointment of Onan - all cures for all illnesses! Roll up good sirs and madams. Guaranteed to Change Your Life!"
A curious crowd gathers.
Invariably, a stooped and coughing man would weave his way to the front of the crowd, glassy eyes desperate for a cure to his croup.
"Doctor, *cough*, I'll have me some of ye coughing brew *cough*".
A bottle lands in a clawed hand and a faintly sulfurous mix is poured down the gaping maw.
An expectant crowd looks on.
"You know Doctor, that ain't half bad. Really opened up me pipes!"
The crowd nods, this Medicine Man has credentials, money begins to change hands.
Later that day after the salesman has packed up his cart, hitched his team of horses and is a half hour out of town he is met by a straight-backed and cough-free man who joins him on the pillion. Tonight when they set up camp they will divvy up the day's ill-gotten takings.