Washing efficacy test apparatus (2) is provided which includes a holder (4) and a test soil device (6) for location with said holder (4). The test soil device (6) is in the form of sheet material with a test soil substance (34) provided thereon. The holder in one example includes two members (8, 10) between which the test soil device (6) is detachably attached so that the device (6) can be easily removed for inspection and maintained in a required orientation in the washing apparatus (2) in use.