Please note that you only need to kill the daemon if it is running. In other words, once you have created the ‘.config/pulse/client.conf’ file on the next reboot pulseaudio should no longer be running. So do you see any pulseaudio processes runing at all?
$ ps aux | grep pulseaudio
Looks like I still see an instance running for gdm. If you don’t need pulseaudio at all you could try uninstalling …
$ sudo apt remove pulseaudio
Alternatively, if you need pulseaudio, you can always use pacmd to play the file …
$ pacmd list-sinks | grep name:
$ pacmd play-file <wav-file> alsa_output.platform-sound.analog-stereo