Regarding the question in post #3. Texas has a new inspection SOP that now requires us to ensure appliances and water pipes are bonded/grounded. That’s been described and discussed several times on the board and specifically in this thread.
Re: post #4 - There’s nothing magical or proprietary about this application of a commercially available Extech CT20(a FLIR company) continuity tester. I simply replace the probes with a more easily used plug, i.e. you gotta get Ground somewhere to use to test the appliance chassis to. No modifications are made to the the Extech itself. Click on the hyperlink in the Extech above or here to see the specifications of that commercial tester. It admonishes, as do I in my use instructions, to ensure that the outlet to be used for detecting Ground is wired and operating properly prior to using the Extech. Again, they do the same thing. My tester makes no connections to the Hot or Neutral pins of an outlet.