Start with collective mocking and then a firm round of shunning.

If what they're doing and saying online gets them ridiculed and then blocked every time they'll eventually have to consider that their thinking is off. This is what's worked for millenia. We need to figure out how to be more effective with that mechanism in social media.

If they can't recruit new men, they'll stop. This is where parents and direct community are failing. I can tell you if Urchling were male and I found her/him doing this shit, she/he would be removed from the internet and all privileges of trust immediately. Parental shock and awe. Same thing about "locker room talk". I have barred a few of Urchlings friends and classmates from our home for some things they were doing. And there were a few friends she wasn't allowed over at their house. This is severe so you don't so it over every little thing, we're not Fundies or isolationists. In my olinions boys are given too much leniency here and excuses are constantly being made for them. "Boys will be boys". It shows.