Product review (3 stars): six month test
The notion of washing my clothes with no electricity, and less soap and water seemed attractive.  So i used the Wonderwash exclusively for the last six months to test it out.

i am a single father who works in an office, but hobbies in the garden.  My laundry battles are kid clothes (food, snot, paint, etc.), office clothes (sweat, ring around the collar) and outdoor clothes (mud, plant matter, etc.).

The wonderwash is not an effective substitute for a mechanical washing machine.

It fits neatly in a tub, seals effectively, cranks easily, and drains quite well. But it does not wash clothes as effectively as a mechanical machine.  Here's why...

A mechanical machine alternates between agitating your clothes for several minutes and soaking your clothes in the soap.  It also rinses and agitates, and spins semi-dry in a centrifuge.

The spin-dry is no big loss.  You wring out your clothes gently, hang dry and their 90% dry by morning.  The wash quality, however, is stickler.

Unless you literally stand over your Wonderwash for 40 minutes, you cannot replicate the agitation and soak routines of a mechanical machine.  Clothes are noticeably and dramatically less clean out of the Wonderwash.

For clothes that didn't go in particularly unclean, that's not a problem.  A casual evening shirt worn once, with no stains will come out looking, feeling and smelling refreshed.  However an item with even the simplest of stains will come out with the simplest of stains.  Your son's shirt that he dropped a few bits of dinner onto will look like you never washed it.  Your work shirts will develop ring around the collar.  Your garden clothes... forget about it.

All stains must be hand-washed/hand-removed prior to going into the Wonderwash.  i found a plastic bristled brush to be a necessary accessory to scrub out stains with the appropriate solvent/enzyme/soap/whatever prior to Wonderwashing.  Aggressive brushing, however, can damage your clothes finish and/or color--be careful.

After several months, i found my clothes to start have a noticeable smell and somewhat unpleasant smell when wringing them out before hang drying.

I countered this last night at the six month mark by taking several loads to a mechanized washer.  One round on  "normal" cycle and they came out smelling great.  For experiment's sake, i washed a load on the machine's "hand wash" cycle... same smell problem... the agitation is everything.

The machine is most effective for barely-worn clothes such as adult knits and delicates.

Although Wonderwash hasn't done me wrong--it's saved me much on the electric bill, and/or trips to the laundromat, it is as yet an imperfect innovation.

i have taken great pains to experiment with different crank-agitation and duration methods.  The best i've found is a series of slow cranks (so no inertia permits clothes to ride over the top) followed by a series of back and forth rocks (a la a washing machine).  Doing this for several minutes and then resting for several minutes and repeating earned me the best results.

i have observed no effect of the pressurization of this laundry method.

i have observed no decrease in water use (multiply out the size of the load and the corresponding rinse).

i have observe no decrease in soap use (a conventional washer likewise requires no more than a few tablespoons of soap--most folks over-soap to the extreme.

If agitation could be improved (either through gearing or adding some sort of fins or something inside...

If a pseudo centrifuge could be added (not difficult engineering...

This could have revolutionary potential.

But as is, it will not change the world.