Is using the hole for the crankshaft position sensor recommended for this job? Which other methods are recommended?

 

No you can damage the flywheel - then the engine won't run
To loosen the bolt without an impact wrench you can take the lower flywheel cover off and find a way to hold the flywheel with the starter teeth, the ring gear. A very large (18-24inches) screwdriver/pry bar can hold it from underneath the car while another person loosens (or tightens) the crank nut - or
You can use the starter - socket and long pull handle placed on bolt, end of pull handle positioned where when it moves it contacts something solid like the frame rail. energize starter for a second - bolt comes loose

 

Or you can use the proper blocker tool which holds down the pulley so you can undo the bolt.




And you should never "blap" the starter which shears off the guide pin on the crank.

There is always the "rope trick". You stuff a rope in one cylinder, turn the crank and as the piston is blocked from moving by the rope, there is enough resistance to undue the bolt.

 

Yes, I own the the proper tool but the techs just use air wrenches. I'd bet that tool is hard to find to borrow when a DIY is doing a cam belt in their driveway. Using the starter simply loosens the bolt, it does not shear off a guide pin for you don't put any pressure on the crankshaft damper - just the bolt.