How to de-program someone?

A close family member has recently gone down the yoga-spirituality pipeline and while the associated beleifs/practices are usually harmless she now has started to believe all manner of crazy things including that people used to live 300 years because of meditation, the moon landing is fake and the titanic disaster didn't happen. I have tried explaining how we know these things are/aren't true but it seems like it just isn't getting through. Her husband is starting to believe all this as well, anyone have any success helping reach people like this?