Would it be good to gargle with salt water?

It is said that elders in the past used to take care of their teeth by gargling with salt water.

I'm wondering if rinsing with salt water occasionally after brushing my teeth would help.

My maternal grandmother does that sometimes, and her dental health is good for her age.

I was thinking of trying it out myself.

It doesn't have to be every day, but would it be okay to do it occasionally?