Maybe not ‘snake oil’ but I’m pretty sure snake wine was (since it still is) available: http://en.wikipedia.org/wiki/Snake_wine
Snake wine (蛇酒, pinyin: shéjiǔ; rượu rắn in Vietnamese) is an alcoholic beverage produced by infusing whole snakes in rice wine or grain alcohol. The drink was first recorded to have been consumed in China during the Western Zhou dynasty and considered an important curative and believed to reinvigorate a person according to Traditional Chinese medicine. It can be found in China, Vietnam and throughout Southeast Asia.
The snakes, preferably venomous ones, are not usually preserved for their meat but to have their “essence” and snake venom dissolved in the liquor. However, the snake venom is denatured by the ethanol; its proteins are unfolded and therefore inactive.
The Huaxi street night market (華西街夜市) of Taipei, Taiwan, is renowned for its snake foods and wine products.
There are two varieties of snake wine:
Steeped: A large venomous snake can be placed into a glass jar of rice wine, sometimes with smaller snakes and medicinal herbs and left to steep for many months. The wine is drunk as a restorative in small shots or cups.
Mixed: Body fluids of snake are mixed into wine and consumed immediately in the form of a shot. Snake blood wine is prepared by slicing a snake along its belly and draining its blood directly into the drinking vessel filled with rice wine or grain alcohol. Snake bile wine is done through a similar method by using the contents of the gall bladder.
http://science.education.nih.gov/animalresearch.nsf/Story1/Making+Medicines+from+Poisonous+Snakes : Snake venom from the Office of Science Edulation.
In fact, there are already two drugs on the market that are based on snake venom proteins and are used to prevent heart attacks. One drug, called eptifibatide, is a modified rattlesnake venom protein. The other is called tirofiban and is based on a venom protein from the African saw-scaled viper. Both drugs have been used since 1998 to treat people having minor heart attacks or those with chest pain indicating they are likely to suffer a heart attack.
So, I guess ‘snake oil’ can be a good thing?