Product review (5 stars): How to Maximize Cleaning
Both the good and bad reviews of this little washer are correct.  It depends on how you use it.

If you spin it slowly so the clothes drop from top to bottom each revolution, the clothes are slammed down through the hot soapy water 60 times per minute.  So two minutes of cranking slams them through the water 120 times and they come out sparkling clean.

If you spin it faster, centrifugal force keeps the clothes at one end of the washer, and you end up with wet, dirty clothes.

I love mine!