I was posted in surgery . I saw a pregnant lady diagnosed with oral cancer . She was around 28 something . She used to use mishri ( a powdered tobacco product ) as a dentrifice daily . It is applied on gums and used in my state widely in rural areas . Their cultural pattern involves using mishri everyday as a mean to clean their gums .
What are some other cultural belief’s you have came across ?
Soaking foot into warm water cures diabetes, lol!
Indians believe equally well in Ayurveda and Homeopathy and everything revolves around Thanda Garam and we spend whole life making these correlations, often without scientific basis. This unshakeable ‘faith’ makes Indians a different class altogether 
Note: For comparison, Americans can not live without ice. Even if there is snow fall outside, ghar / office mein paani ke saath adding ice is a compulsory ritual.
That’s a powerful observation. I’ve come across similar cultural practices—like giving honey to newborns for good luck (which can risk botulism), or applying kajal to babies’ eyes for protection from the evil eye, which can cause eye irritation