coca-cola

Yes your reading is fine and no Dr Shock is still in good health. Discovered this article in the BMJ: Coca-Cola douches and contraception. It appears that

Coca-Cola douches were a part of folklore about birth control during the 1950s and 1960s, before effective contraceptive methods were readily available. It was rumoured that the acidity of Coca-Cola killed sperm, and the classic coke bottle provided a convenient “shake and shoot” applicator.

Why it doesn’t work?

• A toxicology study found that Coca-Cola has only a weak spermicidal effect
• a well placed sperm can reach the cervical canal within seconds, thus escaping the effect of postcoital douching solution.
• Moreover, a coca-cola douche can have severe adverse effects

You can read about these side effects if your interested here. Luckily science has invented better contraceptives since the fifties.