Until the US passed the Pure Food And Drug Act of 1906, later strengthened in 1936, it was totally legal to sell any combination of ingredients with any claim of efficacy, call it medicine and never disclose what was actually in the product.
Much of this "patent medicine" either did nothing at all and relied on the placebo effect. Some of these products really were effective but the ingredients themselves were pretty alarming: alcohol, opiates, cocaine and even radium.
US law has done much to prevent this from continuing without necessarily endangering the customer but there are still a myriad of nonsense products on the market that capitalize on these methods: homeopathics, cold remedies, etc.
The unscrupulous methods used by those olde tyme vendors are still used today, not just for cure-alls but also to sell a lot of other products - many of them targeted towards to the gun community.
We discuss this and more in this episode of InRangeTV.
We'd like to bring attention to these other content creators as we leaned heavily on their work to put together this particular video:
Sawbones (a fantastic podcast about medical quackery from a married couple): http://www.maximumfun.org/sawbones/sawbones-patent-medicines
Vuurwapen Blog (Andrew at Vuurwapen blog takes a highly intelligent and scientific approach to many relevant gun topics of the day): http://www.vuurwapenblog.com/
Canola oil is becoming competitive with synthetics as a motor oil: https://www.hort.purdue.edu/newcrop/ncnu02/v5-029.html