What are you wanting to achieve by turning it off? A reduction in power consumption? Have you observed the power usage when the washing machine is not in use? I know when I looked at a few of my appliances with a similar concept of turning off devices in standby or trickling power overnight or while I was away from home, the pay-off was minimal. Not to say that would not be the case for your scenario, just wanting to make sure you have done the sums.... Easy for many of us to get caught up in the excitement of automating everything 
You may be interested in Better Laundry Monitor for this and other uses, if you are not using it already.
