Just gonna share this one out for all.
While in UT, you can do this live, go to preferences (type this in console) and expand Advanced, Raw Keybinding, Aliases... and add these in.
Use any key and set a key for GemOff
like mine is going to be on O so I type in console: set input o GemOff
What this do, allow you to change the gem share to off or on, with the message there on the top left screen saying it's turned on or off.
You can do this without UT running, just edit user.ini.