I suppose "Why would you want to do that?" is a meaningless question among computer geeks. ;-)
Have you pulled up a terminal window and done `man init`?
Apple has changed so many things that it's a little hard to guess what will happen compared to other systems. For example, during startup you can hold down various keys and it will do different things:
So, for example, command-s during startup will go into single user mode. Don't know if this gets you where you want to go, but maybe it's a start.