Can ruqyah be performed on things other than water, such as food, drink, and medicine? And is it a condition for the ruqyah-infused substance to be poured on the area to be treated, or can it be eaten or drunk?

Ruqyah is permissible if its benefit is proven and it is free from polytheism (shirk) and forbidden things, as indicated by the Sunnah, such as the hadiths of Jabir and Malik. It is also permissible to treat by pouring water on the sick, which was practiced by the Companions and scholars. If reciting (Qur'an) over water and drinking it is permissible, then it is permissible over permissible drinks, foods, and medicines, because what matters is the recited words whose benefit is proven and which are free from polytheism (shirk) and forbidden things.