Well, explaining cryptocurrencies without explaining on how the blockchain functions can be quite challenging especially to people who has no interest in them.

While it may take some time, you can refer to them videos on YouTube (e.g. TedTalk videos on BTC) that explain the fundamentals and basics of cryptocurrencies in general. At first, they would be confused as to how it operates on the blockchain but once they get to understand the principles, they would understand it easier. Another thing, do not force them to know such knowledge as it will only attract disinterestedness from your peers!