It's just too good a bit of obscure Gunn history -
On August 16, Sheffield Edwards sent Dr. Edward Gunn, chief of operations of the CIA's Medical Services Division, a box of Cuban cigars. Gunn was instructed to turn the cigars, thought to be Castro's "favorite brand," into a lethal weapon. Gunn contacted the CIA's Technical Services Division (TSD).
Earman wrote "(Redaction) remembers experimenting with some cigars and then treating a full box ... with botulinum toxin, a virulent poison that produces a fatal illness...."
Gunn experimented with guinea pigs and monkeys to make sure the capsule form of the botulinum was lethal...
being from Chapter 8, Jack Calhoun Gangsterismo; The United States, Cuba and the Mafia, 1933 to 1986, 2013, ISBN 1935928899
Assassination plots included poisoning a box of Castro's favorite cigars with botulinus toxin and placing explosive seashells in his favorite diving spots...
http://en.wikipedia.org/wiki/Cuban_Project accessed 9 December 2014