For those running in QEMU, you can mount the disk that you run your virtual machine from and clean it there manually. See How to find out what's taking space - #2 by kotrfa
Note that I wiped everything in tmp via rm -rf * and homeassistant didn’t start because the container couldn’t bind bind source path does not exist: /mnt/data/supervisor/tmp/homeassistant_pulse. I had to manually add this file into that place to make it work (maybe an empty file would work too?):
# This file is part of PulseAudio.
#
# PulseAudio is free software; you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# PulseAudio is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with PulseAudio; if not, see <http://www.gnu.org/licenses/>.
## Configuration file for PulseAudio clients. See pulse-client.conf(5) for
## more information. Default values are commented out. Use either ; or # for
## commenting.
default-server = unix://run/audio/pulse.sock
; default-dbus-server =
autospawn = no
; daemon-binary = /usr/bin/pulseaudio
; extra-arguments = --log-target=syslog
; cookie-file =
; enable-shm = yes
; shm-size-bytes = 0 # setting this 0 will use the system-default, usually 64 MiB
; auto-connect-localhost = no
; auto-connect-display = no```