Good evening, people!

I have a crab related question. In a bar I overheard the owner talking about keeping small hermit crabs in containers such as a 2000 ml chemistry flask (dunno the proper name, wish I had paid attention watching Breaking Bad). My question would be whether you think it is possible to maintain? I'm thinking a maritime species, something small, maybe in a couple so they would have proper stimuli.

What would you consider a proper set up in such case? I could keep the humidity high in such a container, and I'd place several shells for the crab to use. Any experience with such curious way of caring for a crab?