If you can get a polythene bin of the type used for brewing beer, and it has a food-grade designation, (i,e, it doesn't leach out nasty chemicals), or is actually sold for beer brewing, then you could use that.
I used one of these (20 ltr) for many years for making room-temperature Colloidal Silver with a stirrer (essential) consisting of a miniature aquarium pump. You could even use an aquarium heater to increase the temperature up to about 35 degrees C (about 95 degrees F) if you wish.
I now use 3 ltr laboratory glassware, because I can simmer the DW. Nevertheless, the polythene bin would still be perfectly affective