IMHO, the current Database channel for saving notifications in Laravel is really bad design:
Unlike "Bassem El Hachem", I wanted to keep the database keyword in the via() methods.
So in addition to a custom DatabaseChannel, I also wrote my own ChannelManager that returns my own DatabaseChannel in the createDatabaseDriver() method.
In my apps' ServiceProvider::register() method, I overwrote the singleton for the original ChannelManager class to return my custom manager.