1949: Before he discovered his vocation as a revolutionary, Ernesto “Che” Guevara studied medicine in Buenos Aires. Like many university students, he was strapped for cash, which led him into a series of ingenious but impractical commercial ventures. The most spectacularly unsuccessful was a scheme to manufacture domestic cockroach killer by mixing locust insecticide with talcum powder. Guevara set up a “factory” at the family home, but a nauseous smell soon pervaded the house, he and his “commercial partners” fell ill, and the venture went belly up.
Source: Jon Lee Anderson, Che Guevara: A Revolutionary Life (1997), pp. 57–8