Manziel ought to seriously consider being a party animal character for life now. He might as well start looking for sponsorship gigs from party life products like liquor companies, pot companies from legalized states, beer bong products, and etc. He might as well just ride this "party guy" lifestyle thing on out, and go all in! He could be known that as that athlete that left the league for the good life of drugs and Rock N Roll. He likes that lifestyle any way, so he might as well rub it in everyone's noses and tell everyone to embrace it. He'd probably be happier that way, and then he wouldn't have the pressure to behave.
Personally I don't see that he has really any other options. His football career is completely over in the NFL whether he realizes it or not.