whereupon the old pieces 14 can be exchanged for new pieces 14 and or the old bag 12 can be exchanged for a new bag 12 it should be noted that when the density of the purging apparatus 10 is too great the purging apparatus sinks to the bottom of the tub 20 or settles to a level close to the bottom of the tub 20 at these locations the purging apparatus 10 cannot make contact with the dirt that collects near the surface of the water 22 in the tub 20 and the purging function of the apparatus 10 would therefore be inferior such a heavy purging apparatus 20 may be formed when the only the pieces 14 of inorganic material are included in the bag 20 on the other hand when the bag 12 having pieces 14 of inorganic material is fixed on the surface of the water 22 in the tub 20 to float at only one position dirt is removed from the water only inmmediately after the start of the washing cycle because there is no movement or relatively little movement of the bag 12 or the pieces 14 of inorganic material therein since the purging apparatus 10 floats on the water surface at the same.