I understand that you want the previously run commands to not show up when you use the up arrow mark on the ESXi command line. If yes, follow the below steps in order -
1) Login to ESXi via SSH.
2) Run the command "> /.ash_history" to null the history file.
3) Logout and re-login. Now, it will not show you the previous commands when using up arrow mark.
4) Irrespective of the user, all the commands are stored even in shell.log (under /var/run/log). You can clear that as well using the command "> /var/run/log/shell.log".
Cheers,
Supreet