It's an odd and controversial concept. Hermione is a strong, intelligent character, and Draco is a complex, often - unlikable character in the original. The idea of such a scenario goes against the general essence of their relationship in the books. It might be a form of creative exploration for some writers, but it could also be seen as disrespectful to the original characters and their arcs.
Well, this concept is quite far - fetched. Fanfiction allows for a lot of creativity, but this seems like a very out - there idea. The 'Harry Potter' series has a certain set of values and character relationships. This 'Hermione Spanked by Draco' concept takes those relationships in a direction that is not in harmony with the original. It may attract some readers who are looking for extreme or alternative interpretations, but it will likely be off - putting to many traditional fans.