He also says Joel should do rehab like he did it -- with patients cleaning floors, not watching television.
John says he knows Joel is going to "hate" him for this. But he says Joel needs tough love.
Joel spent a month in a California rehab center for treatment of alcohol abuse in 2005. He spent about two weeks at a Connecticut facility in 2002.
A representative for Joel hasn't returned an Associated Press e-mail request for comment on John's remarks.