What is the ruling on reciting the Qur’an and blowing upon water with the intention of bathing with it for one afflicted by jinn possession or epilepsy?

Spitting into water is of two types:

The first: Spitting with the intention of seeking blessing from the spitter's saliva, which is forbidden and a form of polytheism (shirk), because human saliva is not a means of blessing or healing, and no one's relics are sought for blessing except those of the Prophet, peace and blessings be upon him.

The second: Spitting with saliva that has recited the Holy Quran (like spitting after reciting Al-Fatihah). This is permissible, and some of the Salaf did it. It is tried and beneficial, by Allah's will. The Prophet, peace and blessings be upon him, used to spit into his hands before sleeping with the Mu'awwidhat (Surahs Al-Falaq and An-Nas) and wipe his body with them.