I know they are something of a toothless tiger, but has there been any intervention by the United Nations Human Rights Council in this appalling matter?
His flagship hotel, The London Dorchester, has lost some lucrative bookings as a result, hopefully a lot more in the pipeline. As the Sultan of Brunei owns quite a lot of hotels worldwide, maybe a mass boycott of those would hit him in the pocket, although I think I read somewhere he was the world's richest man, so maybe that wouldn't affect him that much. The west, or indeed any countries who think that these barbaric methods of punishment are unacceptable, should pull out all the stops to ostracise him, maybe a sustained effort along those lines might make him have a rethink.