Don't forget to clear chromes cache and run ipconfig /flushdns on the machine as well.
I found last night that when I set this up it didn't work and today it did - maybe rebooting my PC helped but I often find playing with the firewall rules doesn't seem to have the desired effect immediately. I don't like forcing the routers DNS as I use opendns on the router for the kids and I use my ISPs DNS, hence why I block port 53 for the kids machines instead.
