The silent knobhead works in the same way as the 'magic e' or split digraph, as adding it at the end of a word or sentence changes the sound and meaning of the rest of the phrase. It results from implied use of the word knobhead at the end of a sentence, without actually saying it, thus changing the meaning of the sentence. The benefits of using the silent knobhead are that your conversion should be able to continue without the other party realising that they have been insulted, therefore maintaining and protecting relationships, for example with family, friends of friends, or colleagues.
Fleur: Yes, of course he does. He's probably interested in you for your mind (silent knobhead)!