Need a cleansing experience, in addition to your 8-to-12-week smoothie diet? This week’s show has everything you need to purge the soul. Andy Kindler trots out his Jay Leno and Al Pacino impersonations, Loudon Wainwright III performs several songs off his new album “Older Than My Old Man Now,” and Oscar winner (Sir?) Gwyneth Paltrow, wife of Chris “Coldplay” Martin, honors us with her presence. Plus, the group plays Who Said It! Hee hee! Shamone! Dah!