It solves the issue of secret-sharing much better than any of the other proposed solutions here, including InstaPass. You can post the URL in a public channel with confidence, as even if an attacker accesses the URL, they have to verify themselves with their social identity to decrypt the data.
But yes, it's not end-to-end encrypted, so you're better off self-hosting your own instance of sharelock.
But yes, it's not end-to-end encrypted, so you're better off self-hosting your own instance of sharelock.