Suctioning Phlegm from Dementia Patient. Any Recommendations?

Hello, My father has late-stage dementia and is currently experiencing a lot of difficulty with phelgm getting caught in his throat. We tried an electric suctioning machine, but he wouldn't tolerate it: he has very strong upper body strength still and tends to grab, close his mouth, etc. I was wondering, though, if I might have slightly better luck with a manual form of suctioning. Has anyone tried baby nasal aspirators or even turkey basters? (Or, ideally, something better?) Any recommendations would be gratefully received!!