Little trick ssh console

kill -9 $$

upd:
Grabbed the minuses, well, all so dull?
This command kills the active ssh session, and the entire history of the commands you have typed also leaves, only the last login remains, but about it next time.

upd2:
$$ - symbolizes the ID of the terminal terminal console process (usually bash)
This can be seen by typing:
echo $$
Therefore, the team
kill -9 $$
will kill this process and all its children.
by smartov