How many times do I bathe with the leftover water of someone whose evil eye has afflicted me, and how long is this leftover water valid, and does its effect become void if I leave it for a week before bathing with it?

It has been reported in authentic hadiths that the envier (ain) performs ablution (wudu) and washes the inside of his izar (lower garment), then pours the water from that washing onto the one who was envied (mayun), as stated in Sunan Abi Dawud, Malik's Muwatta, and Imam Ahmad's Musnad. Ibn Shihab mentioned the manner of washing, stating that the person holding the vessel pours the water over thead of the mayun from behind him, then overturns the vessel onto the ground. As for the effect of coffee, there is no known basis for it in treatment. Sheikh Ibn 'Uthaymin mentioned that taking from the envier's waste or remnants has no basis, rather what is reported is washing his limbs and the inside of his izar.