The technique is actually pretty simple: whenever you remember something you want to forget, think of something else instead. My go-to memory is "O Cara Mia" as performed by Rockleetist. I sing the song when I perform my technique, but I don't think that's actually necessary for everyone. Eventually, I start singing the song when I feel like I might remember some nebulous thing that feels like I might not want to, because the neural pathways of the memory and performing the song get interlinked. (probably, I'm 100% conjecturing the neurology of it) Eventually, the neural pathways that led to the memory instead lead to the song, and unless you get a strong reminder, you're unlikely to conjure the memory unbidden.