Healthy gums don’t bleed, and are not painful to floss at all.
I’m in my 30s and only recently learned flossing technique and got my gums healthy. Flossing used to take so long and always involved a lot of bleeding no matter how delicate I was.
These days I’m absolute savage with floss and interdental brushes and never have any blood or pain.
Once you get your gums healthy you’ll be disgusted at yourself for ever not flossing. The amount of disgusting I can floss out on an almost daily basis is insane.
Plus you’re breath will not smell gross anymore.
It’s worth committing to the habit of flossing. Trust me.
Show them this video and tell them this is what happens when you neglect your teeths. https://libreddit.domain.glass/r/popping/comments/py6qlw/teeth_cleaning_i_feel_this_was_the_most/
Nearly nobody will get a mouth that bad if they at least care to look at their teeths from time to time and have a basic hygiene, both dietary and oral.
But to at least get them interested, this video does the work really well.
(The video shows removal of a massive plaque of tartar. So I don’t recommend anyone uncomfortable, with looking at the inside of mouths and with seeing some bleeding, to watch this video)