Using a product other than its intended purpose can be a disaster depending on what it is. Apple cider vinegar for example; people hail it as an all purpose sore throat medication. NIH posted studies also show it can dissolve the enamel off of peoples teeth, and that it is also associated with esophageal damage. The biggest factor being the concentration of the solution. People need to be very careful in understanding these things before engaging in non conventional remedies.
I know someone who tried to cure her sinus infection by using apple cider vinegar in her Neti pot. Yes, she admitted it!
I also knew someone who tried to cure a yeast infection with apple cider vinegar with similarly painful results.
Most people don’t give a lot of thought beyond “sounds good I think I’ll try that!”