This water would probably pull relatively concentrated salts below their physiologically safe level (e.g. sodium, potassium, calcium), making it not useful for leeching out toxic stuff which is usually at a very low concentration. In other words, it would be very non-specific.
People with high blood pressure need salts to be leeched out of their system, interestingly enough.
But not salts like calcium and magnesium, which are essential. As far as I know sodium is the only salt that influences blood pressure.
It might cause water retention issues before leaching anything out.