You have my condolences. I have waged this battle here for some time, without much success. If you press EY on the matter, all he says is something along the lines of "MWI is decoherence, decoherence is MWI", which renders the MWI a redundant concept. Unfortunately, nearly all non-experts here fall into the password-guessing trap, while furiously denying it. Probably because the MWI seems so cute and even intuitive, even if bereft of substance.