You're all arguing about a dumb subject.
Unless your on a rug moving back and forth or getting a balloon rubbed against you while working on something or right before, there is no need for these antistatic clamps. 98% of electronics repair will not be disturbed by you shocking a device as long as you're aware of your situation. Did you wash your hands before beginning work? You all set. Did you happen to get shocked in some other instance before beginning work on a device? Everybody that works with electrical devices has gotten a shock at some point, it just happens. From a device, flipping a light switch, etc. It happens... Just have some common sense when working on low-voltage equipment and touch something metal before diving in to the task at hand.
Always unplug a PC or whatever device you are working on. If it was just drawing power, than you must drain the retaining power. Always press the power button after disconnecting your power source.* Whether it's a plug into a power supply on a desktop or micro PC or Pi, Battery on a laptop, etc. You must drain the current from the circuitry. Than you can work on anything without worry unless you get into soldering and working on the PCB itself.
* FLIPPING THE SWITCH ON A PSU ISN'T GOOD ENOUGH AND FOR BATTERY DEVICES, REMOVING YOUR CHARGE CORD DOESN'T QUALIFY.
Remove the entire situation where a current can reside. Even the CMOS battery can disturb you if a metal arch between that and another piece of metal so watch your tools. IFIXIT makes some great none metal tools; Pliers, Tweezers, even screw bits, check it out... That's just my own personal recommendation so don't dog me for mentioning them.