I've looked briefly into the equivalent of antifascist projects, and former neo-Nazis talking about how their minds were changed. From what I've seen:
- People can and do leave political cults
- There's no universal recipe. A common factor among former neo-Nazis seems to be having someone close to them who doesn't tolerate the bullshit, so to me it seems the best approach is to stand firm, but leave a door open in the rare case that they have a revelation on their own. (Historically, this sometimes happens if/when their own personal reality begins to clearly contradict the propaganda.)
- Many people simply don't leave, so it's unfair to demand those around them spend so much time and effort trying to make it happen. It can be a waste of time. It's a gamble, really, so again that's why I say leave a door open, as long as it's safe.
Obviously these are just second-hand observations, I don't have much personal experience with this, so if any of it sounds wrong then I'd like to know.