Hi Shin,
You can do it easily,
Just switch on anonymous user and make a custom login page. And make that page the default homepage.
Give the annonymous user acces to the custom login page.
This ways, everytime you logout, you'll be redirected to the default homepage that is the login page that you created.
Hope it helps!
Thank you all.
I'm going to try to use "anonymous user" to switch the login page.
changing the sign out behavior seems to be complicated.
Maybe you can find a solution by enabling anonymous user in your case (however be careful to give that user role only the strictly necessary right access).