may have any number of faces 54 but are preferably not round each face 54 is planar and has edges 56 and angles 58 defining the shape of the face for example the preferred embodiment shown in fig2 has three faces 54 and each face has three edges 56 a 56 b 56 c and three angles 58 a 58 b 58 c forming a triangular shaped face each face has a bottom edge 56 c integrally formed on the wash plate 22 and a right edge 56 a and a left edge 56 b that extend upwardly from the wash plate right edge 56 a and left edge 56 b meet at an angle 58 a and angle 58 a of all three faces 54 meet at a common point 60 right edge 56 a and bottom edge 56 c of each face meet at right angle 58 b and left edge 56 b and bottom edge 56 c of each face meet at left angle 58 c it can be seen in fig2 and 3 that left edge 56 b of a first face is positioned along right edge 56 a of a second face and right edge 56 a of a first face is positioned along left edge 56 b of a third face and right edge 56 a of a third face is positioned along left edge 56 b of.