Empty Public Lobby Exploit
All you have to do to create an empty lobby to do Mc/Ceo work is
1.Join public lobby
2.Spam alt+enter for about 15-20 seconds
3.It should say all of they players have left, and you will find yourself in an empty session
been doing this a while, it isn't technically cheating so no ban risk at all
Moved to correct section.
There is another option that works 100% you press ctrl+shift+esc , go to the "performance" tab , in the left corner there is "open resource monitor" go to network right click on gta and press "suspend , wait 2-3 sec or more and then press "resume" , and then you should be in solo session.