a film - supporting device is used with a waste - disposal unit . the device comprises an annular body . the annular body has an annular wall . the inward radial surface of the wall defines a central opening of the body . the outline of the central opening in a transverse plane of the device has variable diametrical dimensions with a first diameter of greater dimension than the second diameter . the outline has two of the first diameter of generally equal dimension and two of the second diameter of generally equal dimension . the device has tubular film about an outward radial surface of the annular body . a free annular end is dispensed outwardly from the annular wall . the free annular end is closed to form a bag . the opening of the bag is accessible through the central opening and is of optimized shape via the central opening for the disposal of waste . a method for disposing of waste on a scooping tool is also provided .