I'm not called to be a poustinik, at least I don't think I am. I gib a little at Bd Catherine's injunction that the bed in the poustinia should be 'a board, with a blanket if necessary', as someone who currently has three blankets on their bed as well as a duvet and a top sheet (the weight helps me sleep). But basically she is outlining how the whole of the Christian spiritual life works, for every Christian, in concentrated form, and so there are lessons to be drawn even for a poor secular priest like me.
The lesson I'm thinking about most is the idea that 'the poustinia has three walls'. In the classic Russian model, the poustinik who takes this on as a long-term vocation rather than an exercise for a day or two, is always available to whoever wants their help, and that help might be spiritual or very practical. Someone might come and seek the poustinik out and say 'Friend, I need some help putting up a fence' and the poustinik must leave their prayers and do as they are bidden. That's the point. To a person willing to exploit, they're free labour. Yet they mustn't complain or resist, but leave it to God to deal with.
One of my Minor Patron Saints (as opposed to my Major Patron, Great-Martyr Catherine) is St Serafim of Sarov, the very doyen of poustiniks, who was wont to greet anyone who turned up at his hut with a beaming smile, outstretched arms, and the words 'My joy! Christ is risen!' I could do with a little more of that spirit, so I am trying to offer thanks to God when the phone rings or the doorbell sounds, treating interruptions as the work of the Spirit. Who knows? I might be entertaining angels unawares. I confess, friends, that I am not there yet!