This also applies to aviation. While pilots execute the same checklist several times each day, year after year, it is still required to verbally call the items on the list. It feels a bit strange doing it when you're sitting in a cockpit alone, but it does really improve accuracy and ensures you're following the same procedure every time whether there is a co-pilot, instructor or nobody sitting in the other seat.
I've never learned actually pointing at the instruments, but I can imagine it helps to focus for example very clearly on doing a check of a specific instrument instead of just saying "checked" out of habit. The problem of course is that you need your hands for other things at the same time, so pointing would be unsafe to do at the controls of a plane.