It doesn't take much to find a laundry shop in Asia, usually for around 40 baht a kilo, but instead of pumping all those extra fast cleaning and more toxic chemicals into mother earth, or using large amounts of energy, an easy and green way is to buy a small plastic bottle of liquid detergent (you can fill it up with the cheaper, dry stuff once empty) and use the bucket for flushing the toilet. You can let your clothes site there overnight and change the water every time you need to flush. I find that a single sitting in soapy water is enough, after which I squeeze dry and rinse under running water, then let sit for another session in a full bucket of rinse water. No need to spend any time moving the clothes around, except for a few seconds with every refill. Then rinse under running water, squeeze dry and hang on your bungalow banister for a few hours and you're done. For more stubborn stains there are various green laundry tricks you can refer to, such as a squeeze of lemon in the rinse cycle and hang out to dry in the sun for a natural way to bleach your clothes. Not only will you be kinder to nature by this, but you will find your clothes will last many years longer.
To help the island save water, as sometimes it runs out and water has to be imported, you can wash your hands and wet your toothbrush with the faucet filling up your flush bucket.