Since open remote is designed to list all available hosts so that a user can select first the host, then the hosted file, I wouldn't be suprised if you can't do this.
If you have windows clients, you might try uninstalling bonjour on one of the lcient machines and then see what appears on Open Remote. Don't know if that will produce an empty dialog or just the Host, but you can experiment and see.
Why do you want to do this?
Removing bonjour will definately result in not seeing the host in the open remote dialog. Although it will render your host completely inoperable even if you input the file address and name.
Perhaps you could configure the hosts firewall not to accept connections from the clients IP.