Currently, the option to allow answering the own question posted is very simple. Either allow it or not. However, if people abuse this feature they can do the comfortable job of only sending the question they already know how to answer and even choose their answer as the best before anyone else can answer.
Instead, it could save a few hours of lecturing if the OP had to wait a given X time in minutes before he's able to post his own answer. How can I make this possible?