The Inca's ability to control the explorers in their trance a hemisphere away could have had a devastating effect on figures throughout history, had they chosen to exploit it.
Could it be that the film version of the "Unicorn" does have the drug that the Incas put into the balls in order to bring the explorers under their influence?
In the original French, Sir Francis Hadoque's adventure takes place in 1698 and he serves Louis XIV. The War of the Grand Alliance (1688–97) had just ended and by the Treaty of Ryswick, Louis had acquired Saint-Domingue (now Haiti) from where the "Unicorn" has left before encountering Red Rackham and his pirates.
I've just been reading a book on the Battle of Blenheim which took place 6 years later (1704) and how it ended Louis' hopes of dominating Europe. Using the Inca powder and method of long-distance torture on the enemy commanders, the Duke of Marlborough and Prince Eugene of Savoy, would certainly have "changed the course of history".