This method of dish-washing saves energy by minimizing the amount of hot water running right down the sink and away, which can be a fair amount. It also saves water via the same simple action of plugging the sink -- two birds with one stone, always good.
The added use of soap-nut detergent makes it even more efficient by being biodegradable and can be used to water your plants with.
Washing dishes this way won't save as much energy as the amazing Satellite CD Solar Oven, but it makes the daily ritual of cleaning your plate sacred by actively respecting Water and Earth.
First hand account of using soapnuts.
More practical information about using soapnuts and links to several online soapnut retailers from North America, UK, New Zealand and Australia: soapnuts.
Step 1: Prepare Soapnut Detergent
3 quarts (litres) water
Step 2: Simmer 30 Minutes
Bring the water to a boil. Turn down the heat to a low simmer for at least 30 minutes. Or use the Hay Slow Cooker for greater efficiency.
Step 3: Strain
Allow the liquid to cool, then strain out the soapnuts.
Step 4: Storage
Funnel the liquid into an old detergent bottle. This product is all natural so keep it in the fridge when the temperature is warm -- it doesn't have as long a shelf life as commercial products and is completely biodegradable.
This liquid can also be used as a vegetable and fruit wash, all-purpose cleanser (great on floors), laundry detergent, shampoo or to get aphids off a favorite plant.
Soapnuts are anti-bacterial and anti-fungal, efficient cleaners but they don't suds up to the degree we are accustomed to these days, but have no fear. Your dishes are as clean as can be.
Step 5: Prepare Dishes for Washing
Quickly rinse dishes with a minimum amount of cold water.
Step 6: Clean Out Sink
Clean out your sink and put in the plug.
Step 7: Fill Sink
Start to fill the sink with hot water.
Step 8: Add Detergent
Add about 1-2 Tablespoons of soapnut detergent.
The water will suds up, but the suds quickly subside. Don't worry the soapnut detergent is still doing it's job.
Step 9: Wash Dishes
Wash dishes and place in dish drainer to dry.
Step 10: Remove Used Dishwater
It would be easier to use a plastic tub at this point, but I don't have one the right size for the job, so I just ladle out as much of the used dishwater as I can into a bowl.
Step 11: Dish-Water Your Plants
Water your most needy houseplant.
I'm looking into growing my own soapnut plant next -- then it will truly be cradle to cradle dishwashing.