Yes, this works without any IT, if you trust him. Until he defaults and you have nothing to show in the court.

SwapMarket

I run the local store and a local comes in to buy the usual bread and milk every fee days. Today he comes in but the internet us down. He takes the bread and milk and I write on the blackboard behind the counter that he owes me money for these items. Next time I expect him to pay.

This isn't a communist utopia. It's localized credit.

lightning

The cheapest Lightning setup that actually works (tested in Cuba)

claos545

What I mean is this: 

I run the local store and a local comes in to buy the usual bread and milk every fee days. Today he comes in but the internet us down. He takes the bread and milk and I write on the blackboard behind the counter that he owes me money for these items. Next time I expect him to pay.

This isn't a communist utopia. It's localized credit.