sudo mkdir /Library/Application\ Support/ViscosityScripts
sudo cp disablenetwork.py /Library/Application\ Support/ViscosityScripts/
Add the following line under Advanced for the Extra OpenVPN configuration cmmands:
route-pre-down "/Library/Application\\ Support/ViscosityScripts/disablenetwork.py"
Run the following once before connecting:
/Applications/Viscosity.app/Contents/MacOS/Viscosity -setSecureGlobalSetting YES -setting AllowOpenVPNScripts -value YES