As a matter of fact, the very first successful S/H pot had, in a former life, brought home won ton soup from the restaurant!
Any plastic container can be used - be creative. I cruise big-box stores, dollar stores, etc. for likely containers. I have used vases, small trash cans, even styrofoam coolers. They don't have to be clear, although, while opacity does prevent algae growth, it does make it tougher to see if the plants need watering.