XMPP Onion Serivce Only (no clearnet)

Does anyone know if there’s a guide showing how to create an XMPP client and login only using Tor Onion Services?

Even the docs at coy.im (probably the most secure-by-default XMPP client) suggest that you use username@coy.im. No, I don’t want to enter a clearnet address anywhere.

Is it possible to use only a .onion to create and login with an XMPP account?

See also: