I was brought up to do this as a matter of course,even though it was never a huge advertised teeth-care subject as it is these days. My dad at 86,still has akll of his teeth and I do believe the flossing has helped in this being so!
Yes, I floss every night after brushing. I also used listerine, but now I don't use it too regularly. Years ago I had bleeding gums and had to go to a periodontist. Eversince I have looked after my teeth with regular flossing and now when I go to the dentist for my regular clean and check ups I am always told that I am looking after my teeth well. Yes, it is a small effort, but really worth it if you want to save your teeth.