I have about 2500 hours 985s and 1340s and we never pulled the props through.
800 hours 1830s on a Dak - always pulled 'em through.
1200 hours 1820 on Trackers (Firecats) never pulled them through.
Never flew the DC-6 but was around them LOTS and they never pulled them through.
Now, counting blades on the starter before ignition, another story. Always.