You can’t nominate your own self-MOC, but it doesn’t have to be someone well-known. In fact the aim of my project is to get as many community members’ names in the hat and built as I can.
A slip goes into the hat for each nomination, so if a self-MOC is nominated multiple times that does make it more likely to come up sooner, but it’s no guarantee.
So, if you have a friend in mind or just someone you’ve stumbled across with a cool looking self-MOC, absolutely nominate them.
There are rules written on the project page.