Install run-as, a bash and a python script which wrap up usage of machinectl, xhost and of managing running dbus and setting variables for you:

run-as <user> <command>

To run a graphical application do

run-as -X <user> <command>

Read, copy and install run-as, a Bash and a Python script which wrap up usage of machinectl, xhost and of managing running dbus and setting variables to run a graphical application for you:

run-as <user> <command>

To run a graphical application do

run-as -X <user> <command>

References

• xorg - How to run a graphical application as another user? - Unix & Linux Stack Exchange