I don't think you'd even need to block the non-royals for this to be effective. If France and/or the UK put anyone with "Al-Saud" in their last name on a no en

I don't think you'd even need to block the non-royals for this to be effective. If France and/or the UK put anyone with "Al-Saud" in their last name on a no entry list, MBS would be gone in weeks.