not sure about using messages... can you make your query/reponse into 'iq' packets? maybe this will work with messages also, i just haven't tried. this is from a bot that gets a list of users in chatrooms.

while (1) {
        $count_rooms = 0;
        %count_users = ();
        open $html, '>:utf8', 'chatters.html';
        print $html qq{<h2>Currently in Chatrooms</h2>\n<ul>\n};
        my $Rep;
        $Rep = $Connection->SendAndReceiveWithID(
                new_get_iq($ME, $CS, $NS_D_ITEMS),
                10);
        rep_dump( $Rep );
        print $html qq{</ul>\n};
        close $html;

        print "Count: $count_rooms rooms, ",scalar(keys %count_users),
+" users\n"
;
        sleep(60);
}
[download]

the SendAndReceiveWithID function will send the IQ Query and wait for the IQ Response before continuing.