Apparently some confusion here, as you posted this:
"He thought it should work it's way down to a single time in the end."
It does, that is exactly what I posted:
"Rotate the dial to the right (clockwise), stop when you reach the third number in your combination"
That is one time.
If you are having issues when you KNOW for fact the combination is correct, make sure you jiggle the door when turning the handle first.Sometimes the bolts dont want to slide easily and the jiggle allows them to move easier.
If that does not work:
Older safes sometimes can become off point.That is to say, you may need to go past each number a fraction, do not stop on the number, but do not go past the number to the next number.Stop just past.
Do that on each number and try.
Make a very small increment each attempt, if the first one does not work.
The dials can become loose and tight over the years and this works many times, just no guarantee.
Keep me posted