Just need a simple tub with lid, size is dependant on how many you need
I use an old bird fatball tub which used to hold 50 balls(punture small holes lid)
I mixed my old gravel with clean earth/compost dryish type then sprinkled
with calcium/carbonate lime which help with PH and provides worms
with extra calcium;
All thats required add nightcrawlers and feed which can be purchased or sourced.
The worms must be free from fertilizer or chemical source
The feed can simply be grounded oats fed frequent but sparingly.
So far 3 months no issues with smell, my worms are sourced via online
and the worm/tubs kept in dark room where it nice and cool.
This not ideal for breeding but perfect for a week/fortnight continious supply
Keep moist with spray when required