Hmm... there's always /nickserv identify, but I have absolutely zero idea how that even works.
What if you made your own bot that listened for private messages from users, and verified them? So all I had to do was /yourbot julian hunter2?
Then your bot would probably communicate with a companion plugin on our end to verify users by username/password... There's a possibly MITM issue present if you don't use HTTPS though... less so if everything is on one machine and you're communicating via localhost connections...