How to clear a password

Hi folks,
how would you clear your set password to an empty one? I use external auth and so I don’t need passwords at all. For some testing reason I’ve set some to some users (and also for my Admin one) and now the password is wanted every time I am creating some token for example. So far I’ve found only setting it by hand in database, maybe set the minimal password length to 0 and then use
$user->SetPassword(''); code. Is there other option?