Could a bunch of people in a room set up a manual "blockchain (or other DLT)"?

I was wondering about this to get a clearer idea of how the idea behind Blockchains could be applied in different contexts.

So imagine there are a hundred people in a room. Each person has some money stashed at home and some goods to sell.

Is it possible for them to set up an analog/manual "blockchain" or other distributed ledger system without using an actual blockchain? What is the least amount of technology they could use, whether they need to use text messaging, or pen and paper, or a whiteboard? Does each pair of traders need a witness? Three witnesses?

If this has already been explored, feel free to link some resources. Thanks!