I've always just done touch ~/domain/path/index.fcgi to "restart" my FCGI process, although that's only if you're not running an external fastcgi server.

If you've got a host like Dreamhost that kills FCGI processes aggressively, try a curl call (using cron): */15 * * * * /usr/bin/curl -s http://domain.com/dispatch.fcgi 1>&2 &>/dev/null and that should keep your FCGI process alive.