Is there much of a link between flossing and/or using mouthwash and infective endocarditis?

Good oral hygiene: We know there is a link between gum disease and heart disease. It sounds like you might be practicing good oral hygiene habits. For that i commend you. If you don't have a problem endocarditis then the procedures should affect you. If you do have a problem then the likelihood of them causing a problem, in my opinion, is very minimal.

No: For the most part, flossing and mouthwash use would lower the chances of endocarditis by keying less infection in your mouth. Bacteremia, an large influx of bacteria, is caused usually. By a more traumatic act, like a tooth extraction.