Sometimes Holmes got things without even trying. For example, he got all the dogs in the neighborhood to howl. That invariably happened when he started playing the violin. I also wanted to howl, but at that time it did not look good that a man howled. So I was content to lock myself in my bedroom and whimper. Is that Holmes only played the violin when he felt sad. A sad man in possession of a violin without having the most basic knowledge of how to play it, has got in his hands a tremendous power over others. So much so that hearing Holmes play the violin inspired Lestrade a revolutionary procedure to extract confessions from criminals.
And since I have brought up the topic of blackmail, I am going to refer to a case that has not reached public opinion but had been driving Scotland Yard nuts until Lestrade put it in the hands of Sherlock Holmes.
It turns out that His Royal Highness Duke of Cambridge began to receive anonymous letters where he was threatened to divulge a certain secret that, obviously, now I am not going to reveal here. (Suffice it to say that it was related to the pigeons of the London parks.) The demand of the blackmailer was that, in every public event, the Duke should walk on all fours, a requirement that he fulfiled to the embarrassment of the rest of the Royal Family. Scotland Yard had intercepted some of the letters at the time of being thrown into the mailbox, but could not find its author. It occurred to Holmes that the person who introduced the extortionary letter in the mailbox might have to do with the blackmailer. And indeed, such proved to be the case. When the individual in question was arrested, the threatening letters ceased and His Royal Highness was able to recover the upright posture, although from time to time he still attended protocol and formal events on all fours, but it was already of his own free will without coercion by anyone.