That's why banning specific toxic behaviors work, it encourages introspection for people whose bad behavior is unintentional.
Instead of turning it into a negative thing, you could make it a positive. Like, instead of feigning surprise to shame someone for their lack of knowledge, take the opportunity to teach someone something valuable, if they'd like to learn about it. Encouraging people to think this way and help others is going to be more positive than a negative like a ban, and thus probably be more effective towards positive change.
Say a cofounder who is the classic combination of huge ego and low competency. When addressed about being respectful, a typical response is, "but I don't respect them."
They may have suffered major emotional abuse from a parent and won't be able to correct those flaws easily.
As a recent example, see the Noisebridge debacle over having to actually add rules.