Intuitively, I'd say the latter isn't to actually stall the prop, but rather to make the slipstream driving it get so small that the friction from rotating the cranckshaft etc makes the prop stop.
One indicator: It's easier to stop the prop this way when flying something with a big engine (i.e. takes more energy to turn over). As this normally means you fly something with a higher stall speed (=more slipstream), I guess a condition should be that a/c stall speeds are the same.
Anyway, I'd go for DB6's description.
Cheers,
Redbar1