1. change the permissions on the executable so that only root can run it. The normal firefox program is actually a script, so make sure you protect all executables in that directory.
2. Set up
sudo to allow the user george to run it.
Now, having said that, I highly recommend against giving George your root password. If you want only George to run this program, sudo prompts
for his own password. But it's possible to configure George so that he can run the program without a root password.
Having said that, I also highly recommend against giving George the ability to run firefox as root. Instead, specify another (new) user (ie, "firefox-user") that can only run firefox, by changing the ownership of the entire firefox directory to that user. Configure sudo to "run as" that new user.