Dr. Bronner's Organic Castile Liquid Soap
This biodegradable soap can work for just about anything--hand soap, showers, shampoo (though I don't really recommend that), laundry (haven't tried it), general cleaning, washing windows, brushing teeth (not going to try that), etc., etc. We try to keep our grey water "green," so we're careful about any products used in the tiny house. This fits the bill. I love the almond scent the best.
To get more information and to purchase this product (or anything you're planning to buy on Amazon!), please click on the Amazon link below. We'll get a teeny, tiny commission on your purchases—and it won't cost you a thing!