The OpenVPN config file structure on ClearOS is non-standard (For example there is no server.conf), so I was unsure where to put the directive. However, as it turns out enabling the Management console is as simple as adding the following to /etc/openvpn/clients.conf:
management localhost 7505
The port is arbitrary: any unused port will do. Localhost restricts connections to the local machine, which is smart if you do not have a password to secure the connection.
To access the management interface using telenet, issue the following from the clearOS box:
telnet localhost 7505 #When the prompt comes up, issue a command such as "status"