Option to flush input buffer

[Ron Steinke]

        Is there a configuration option to flush the input buffer
in ssh? Specifically, I'm trying to run

ssh -F $HOME/.rn_ssh_config -l username remote.host rn +x +X -I

and I have to hit <return> before my input is forwarded to rn. These
additional <return>s are also confusing rn. Is there some option
I can stick in the configuration file to help this?

                                                        Thanks,
                                                        Ron Steinke