This was very interesting, but sadly: https://github.com/ipfs/js-ipfs/tree/master/examples/exchang...
> Note: As js-ipfs@0.29.0 currently doesn't support DHT peer discovery, the peer from which you are fetching data should be within the reach (local or in public IP) of the browser node.
The PR to implement DHT has been languishing since May 2017: https://github.com/ipfs/js-ipfs/pull/856/files