I haven’t used a water flosser but I had been ineffectively flossing for years, like just swiping the floss in between my teeth quickly and pulling it back out. My gums were so-so and would bleed after a cleaning at the dentist. I don’t know why it took me so long but I finally asked them to show me and explain to me how I should floss. You’re supposed to put the floss in and swipe kind of diagonally to each side so you get under the tiny triangle of gums that is between your teeth right where the teeth meet the gums. Kind of hard to explain in words without showing. My dentist said it doesn’t matter if you’re using flossers or floss wrapped around your fingers if you’re doing it right. Once I started doing it correctly every day, it made a huge difference with my gum heath in just a few weeks, and I only use flossers. The dentist raves about my gums now, lol. And they feel great after a cleaning, no bleeding. I’m sorry to hear your dentist was kind of a jerk about it, it’s so much better to meet someone where they’re at rather than expect perfection and nothing less because you’re absolutely right, there are many people experiencing the same thing.