This works great on servers and lightweight desktops. As others have noted, if you want GNOME you also need to install systemd-shim. I have no experience with this, but I have no reason to doubt that it works.
I'm running openRC on all my systems and the problem is usually dependencies. As an example, both Brasero and K3b depends on something that depends on systemd. I can understand if a program uses the systemd library but these need systemd as pid 1 because reasons.
To replace PID 1 with sysvinit, run:
To prevent it from coming back, create the file /etc/apt/preferences.d/no-systemd.pref containing: This works great on servers and lightweight desktops. As others have noted, if you want GNOME you also need to install systemd-shim. I have no experience with this, but I have no reason to doubt that it works.