How to toggle "invisible mode" with Real ID!

So I was poking around looking for a way to turn off real ID for a bit while playing on an alt and came across some interesting information.

If you log into WoW, and go to your firewall settings and block all outgoing TCP connections on port 1119 with your firewall, it disables your connection to the real ID server on battle.net, while still allowing you to play the game. You can't see who is online on Real ID and your Real ID friends can not see you. To re-enable you just have to allow the connections again, and restart the game.

Fairly painless, made a little program to toggle it on and off with one click. Just thought I'd throw that out there for people still looking for a bit of privacy, while wanting to maintain the use of Real ID.

I know there are parental controls and stuff but never really messed with them, it might be similarly easy that way I don't know, don't hate if it is!