Find friends, the less familiar with the space the better. Ask them to write down facts about the product, in the order that they learn them. After each navigation, ask them to summarize what the product is and what problems it solves.
That’s basically the approach I took when writing that up.
I think the unfamiliarity is the most important part. It’s incredibly easy to be blind to what you know and others don’t. It also simulates a non interactive cold sell for the product, as opposed to trying to convince your competitor’s customers to jump ship.