I have been watching Supernatural and other shows that include demons is it possible for salty water to effect demon, Ghost etc. or is it just grain of salt?
In certain Christian traditions, holy water is a mixture of salt and water that has been blessed by a priest. Witches, vampires, and other nasty evil creatures were considered violently allergic to holy water. In the middle ages, due to the demand, there was even a delivery service for holy water in cities, like the milkman in the 20th century.