My dad was a manager at a toilet paper mill. After seeing all the chemicals, acids, dyes, and stuff that goes into toilet paper, I wouldn't use it to filter my oil, even with the "john wayne" paper that these filters were designed for. Pulp is very corrosive to iron. The detergents in the oil may get most of it, but if you really want to filter the oil this way you should use lens paper or kimwipes.
