As we all know, washing clothes use lot's of energy.
When going to your work with a car. Fill a sink of water and put some power and your clothes in it. Place the sink to the trunk and drive. At the point you reach the office, your laundry is all done.
On the way home, put the clothes to the windows so those are hanging outside. At home you have clean and dry loundry free of charge!
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In Finland we call these as "Niksi Pirkka" tricks.. and there is tons of these
-P