I am actually going to watch it so if this joke you speak of is just him doing the bit where han solo gets sealed in that shit except he's mooning I'm going to inform you of how big of a fucking idiot you are.
E20 yes, it is being released as a DVD in time for the Christmas sales season (instead of airing on TV first). The episode numbering is just in line with one of the television databases online.
I might watch it, but I really go turned off by Family Guy as the years went on. Before it was about getting around the FCC, saying extremely controversial things, and offending people. Now it's just HURP DURP IM A MONKEY bullshit comedy.
Family Guy is about the unfunniest series ever. Most of the people who watch that crap are teenagers to feel so grown up because they say some swear words in a cartoon. Same goes to South Park.