Recycle detergent bottles by washing your small items in them.
I developed a cold while skiing in Canada, and found myself with too few handkerchiefs. Our hostel had a laundry where you could wash clothes, but it seemed wasteful to run a whole load for several handkerchiefs. I found an empty liquid-detergent jug in the laundry room, partially filled it with hot tap water, stuffed the handkerchiefs in, put on the cap and shook it for 30 seconds. Next, I rinsed several times and then pulled the clean handkerchiefs out. It was remarkably effective.