"Tip: Additionally, you may use a cord to attach a USB key to your wrist. Then insert the key into your computer and start usbkill." This line particularly caught my eye. I wonder what's the percentage of people (I'm presuming people working in security or those who are trying to avoid detection) go to this extreme? Is is even extreme?
How about a bluetooth dongle in your pocket? Less visible, and unless there hostiles know about it, they will separate you from the computer. A phone could work. An apparent car key would be better. Best would be a piece of clothing, like a belt.
That would work great for half an hour, until your Bluetooth connection drops for no reason, the dongle pairs with your car or phone instead, decides it's a headset now, or one of the hundred other things that inevitably go wrong with Bluetooth.