A good reason to keep that worn out socket.
I did mine a different way. I put the torque wrench in the vise sticking out and vertically hanging down rather than horizontal. I didn't use a socket, just the square in the vice with soft metal to protect it. I measured 2 foot on my particular wrench and marked it on tape. Used a 16kg kettle bell to gently hang off the tape at the mark with the torque wrench set to 70foot lb and heard it click, then put it to 71 and heard it not click so was happy as 16kg is 35.2lb and needed to be 70.4pounds at two feet. So my wrench will click somewhere between 70 and 71 and 70.4 is pretty well in the middle.
I think I prefer my method as his means having to look at the scale that is not that steady as he pulled on it.