Product review (5 stars): It's a Wonder, all right.
Some of the reviews mentioned the weight of the tub when filled with three gallons of water (a gallon weighs around 7 pounds), so I searched Google and found a supplier of beer and wine making supplies and ordered a plastic spigot.  I installed it at the bottom of the tub so I could drain off most of the water before removing the wet clothes.  By placing the wash tub in the bathtub, I could also fill it with water and rinse right in the tub.  The Wonder Washer does a fine job, and saves wear and tear on my full-size machine, which is getting on in years (like me!).  It does tend to move around when reversing, but I've never needed more than two or three minutes to get results, so I just hold it in place.  No problem, and an excellent buy!