This is not true. In fact, Guix doesn’t use systemd at all. When managing an operating system installation Guix uses its own init system called the Shepherd.

Elogind is a project extracted from systemd originally for use in Guix systems.

Here you go: https://adnauseam.io/

If you wanted to do it in one query I think you could do something like

UPDATE local_user AS u
  SET u.totp_2fa_url = null,
      u.totp_2fa_secret = null
 FROM person AS p
WHERE p.id = u.person_id
  AND p.local
  AND p.name = 'guineapig';

I assume the p.local is optional, too, because the id match against the local_user table will presumably limit it to only local users. 🤷