Having pulled the prop through to clear potential hydraulic locks, it is also usual to pull the prop through when priming a cold engine, one blade per shot on the primer pump.
The colour illustrated translation of the original Russian Yak-52 manual shows that once your enlisted ground crew have finished doing this for you, the head of the ground crew delivers a crisp salute to the sky-god in the cockpit, who then proceeds to start the engine (and everything disappears in a cloud of smoke, although the manual doesn't show this).
I've repeatedly shown this diagram to the Waltham donglers, but the only salute I've been delivered with thus far was of a cheerfully un-military variety.