man 5 ttyaction

You could try putting an entry in /etc/ttyaction for a shell script
that figures out the TERM and sends the appropriate sequence.  You
have a variable $TTY to help you figure out the term.  A sample entry
from the manpage looks like this:

tty0    getty   /somewhere/tty_clean ${TTY}

YOu can change that to:

*   getty      /somewhere/tty_clean ${TTY}

Note the fields are described thus:

     ttyname   Name of the tty line(s) on which this line should
               apply. The name is relative to the /dev directory,
               similar to how such de- vices are named in the
               /etc/ttys file.

     action    Name of the action for which this line should apply.  The
	       action names currently defined are "login", "getty",
	       "telnetd" and "rlogind" which indicate which program is
	       processing this file.  (Note that "login" begins a
	       login session, while the other three are run after a
	       login session ends.)other three are run after a login
	       session ends.)

     command   What command to run if this record matches.

I've confirmed you can do something like:

*    getty     echo foo > /dev/${TTY}

To send a message.  It should be relatively straightforward to replace
that with a program that figures out the TERM on /dev/${TTY} and calls
tput with the correct parameters to clear the screen.

Regards,
James Wetterau