Hamster got too hostile and really want to get out of his cage

So my partner didn't know about the sand bath and tried to bath my hamster with water and soap as a good gesture and didn't realize how harmful it was, anyway after the incident the hamster got very hostile and bites whatever around it, and he's biting his cage and trying to open the door so bad. I'm not sure what to do to make him calm down and trust humans again and beat the trauma. Can you guys help?