Stop pulseaudio from restarting under gdm/systemd! Other answers do not work!

When I boot (Ubuntu 18.04), systemd is starting up pulseaudio under user gdm. I don't want that - I want to run pulseaudio as my user, because of problems with pulseaudio under gdm and mpd.

So I am trying to kill it, and nothing will kill this monster. It keeps respawning. People have asked this question before, and all of the following solutions have failed:

1. Add "autospawn=no" to "/etc/pulse/client.conf" Add "autospawn=no" to "/var/lib/gdm3/.config/pulse/client.conf"
2. Also add "daemon-binary = /bin/true" to client.conf
3. "sudo rm -f /etc/xdg/autostart/pulseaudio.desktop"
4. "sudo systemctl kill pulseaudio" (Returns "Failed to kill unit pulseaudio.service: Unit pulseaudio.service is not loaded.")
5. Removing /etc/xdg/autostart/pulseaudio*
6. systemctl --user stop pulseaudio.socket
7. systemctl --user stop pulseaudio.service
8. systemctl disable pulseaudio

According to pstree, it keeps getting restarted by systemd with user gdm, if I kill it (as root) the process dies, and systemd just respawns it.

But I can't figure out why systemd is starting it:

% systemctl --type=service | grep pulse
% systemctl list-units --type=service | grep pulse

In fact, systemctl doesn't even think it's running:

% systemctl | grep pulse
% systemctl --state=running | grep pulse

Which is why:

% systemctl disable pulseaudio
Failed to disable unit: Unit file pulseaudio.service does not exist.

And systemd doesn't admit to starting it:

% systemd --test | grep -i pulse
Loaded units and determined initial transaction in 27ms.

But pstree tells us that it's lying:

% pstree
    .....
    |-systemd-+-(sd-pam)
    ...
    |         |-pulseaudio---{pulseaudio}

It's also not listed in the init.d or Xsession.d scripts:

% ls /etc/init.d/*pulse*
ls: cannot access '/etc/init.d/*pulse*': No such file or directory
% ls /etc/X11/Xsession.d/*pulse*
ls: cannot access '/etc/X11/Xsession.d/*pulse*': No such file or directory

Although this file does exist:

/var/lib/gdm3/.config/systemd/user/sockets.target.wants/pulseaudio.socket Which claims "WantedBy=sockets.target" whatever that means..

I think it might be partially a path problem with systemd - it's not in the /etc/systemd path:

% find /etc/systemd/ -name '*pulse*'

But:

% find /usr/lib/systemd | grep pulseaudio
/usr/lib/systemd/user/pulseaudio.socket
/usr/lib/systemd/user/pulseaudio.service

I noticed that someone else had this bug on redhat:

https://bugzilla.redhat.com/show_bug.cgi?id=1635119

Frustratingly it was closed as NOTABUG without an explanation.

What does it take to kill this process and keep it killed, without some hack like temporarily moving the binary?