Isn't it common that shitty places, like a fries stand in a village festival or in tourist areas, recycle oil all the time, and the food tastes like bad oil?
My friend once asked a guy at the fries stand if he changed his oil this month. The guy was visibly shaken and said of course he has, this oil is no more than a week old.
Yup. Shit is gross. Still, the image of people recycling sewer sludge into cooking oil is burned into my brain, and an order of magnitude worse in my perception.