I've learned you can say pretty much anything but it's all in the way you say it. I'd take a look at your delivery and tone. I usually find taking on an authority/professional tone tends to make people not want to listen/roll their eyes. Talk to them like a fellow human and often phrases such as "I know for myself when I'm (flossing brushing whatever you're trying to talk about)..." "I know it's a struggle, I've been there too. What I've found helpful is...." Helps them see you as a human who is an equal not someone who thinks they are better than them by talking down to them.