Only once per day, in the evening before bed. I have done it all my life(except when I was a kid) and it seems to work for me. Never had any issue with my teeth, at all. I know I should probably do it in the morning aswell, but I cant bother since what I do now works…
My wife is pretty sensitive to smells, so I’m sure she would tell me if that were the case. Also, I practise intermittent fasting, so I don’t eat anything before lunch, maybe that helps…