3-Ounce Plastic Bathroom Cups. 1 Package of 150 The small 3 oz plastic cups can be used as mouthwash cups, bathroom cups, tasting cups, party tumblers, drinking cups, jello shot cups, dental cups and rinse cups. The compact size cups make them easy to grip for even the youngest. While the classic appearance is also suitable for home, events or business use. These plastic cups have sturdy walls, and the horizontal textured walls of the cups provide a non-slip grip, perfect choice for bathroom cups of the whole family. While plastic cups have rigidity and strength that paper cups do not have.