There are two techniques to override local client side DNS resolution. This can either be done onthe client with the etc/hosts or by using a SOCKS tunnel in Firefox.
On the remote Service ensure that the ORIGIN authority resolves to an IP address of one of the host's network interfaces.
On the client change the authority to resolve to the IP address of the remote host. On Mac and Linux the file is located in /etc/hosts, on Windows it is in %SystemRoot%\system32\drivers\etc\hosts
On Mac the following must be run after any changes to /etc/hosts.
sudo killall -HUP mDNSResponder
On the client run the following to setup a temporary SOCKS tunnel to the remote host.
ssh -D 8080 example.com
In Firefox open about:config in the address bar. Enabled network.proxy.socks_remote_dns and add localhost:8080 SOCKS proxy. This will proxy all Web traffic through the SOCKS tunnel and use the remote server for host name resolution.