The situation was that Rachel did see Chandler wearing a shirt, boxer shorts and socks, but because of the compromising position that he was in and the lack of other witnesses, she was free to make up whatever story she wanted about what she saw, when she told others. The actor can wear clothes and these can be kept out of shot with good editing. Jessica Alba did it this way for the well-known nude shower scene in Machete. She loves running, water skiing, writing, watching Christmas movies all year long and The O. When she got the award in her country for the movie her porn star past was exposed. The easiest is for the actor to be nude and for editing to ensure that the finished film is decent and their modesty is protected. However, for season four, the show's producers cast a number of genuine adult film stars, including Jessica Jenson and Samantha Bentley, winner of the Adult Video News award for Best Group Sex Scene, who both play prostitutes on the show.
