I feel that many of the comments for 'Swept Away...' slightly miss the point. Certainly, it is about politics. But Wertmuller is not taking sides between her communist & capitalist heros. She is examining what happens when they are removed from the society that defines their roles and their relationship.
Once the balance of power is reversed, they essentially change places. He becomes dominant (and often abusive). She becomes weak and submissive. The rough sex, etc. is all symbolic of how the poor are treated by the rich. And Wertmuller shows us that the 'working class hero' has no inherent nobility. Put in the position of power, he is every bit as cruel as his former oppressors. Once they return to society, the balance of power is once again reversed.
The message here is that there are no political heros and villains. Power is relative and arbitrary. And sadly, it is our nature to abuse it. The lesson is, perhaps, that we must rise above that base instinct and treat our fellow men with empathy and generosity. "We have met the enemy, and he is us."