Assuming you didn't do these evil deeds, having video or audio proof(if legal in your jurisdiction) is really the only way to counter them.
Otherwise, what do you say? "No, I didn't rape/sexually assault this person". The accusation alone is salacious enough that a mere denial isn't going to change anyone's mind.
And I would say that the women's accusations, if true, would be bolstered if they had video/audio evidence of it.
Well, the traditional solution to this is to just cross-examine the accusers about the cut of their skirt, whether or not they had any idea what they were doing when you invited them to the hotel room, how many casual sexual partners they had, and all sorts of other bullshit that's completely irrelevant to whether or not they were raped or harassed.
It tends to work pretty well for people who are actually guilty, it should work even better for the innocent.
If you are a public figure, and you never sexually assaulted anyone, yet multiple people were accusing you in public of doing so, how (if at all) would you defend yourself?
(It's one of the reasons why people think twice about accusing the guilty.)
> First, the plaintiff must prove that the defendant made a false and defamatory statement concerning the plaintiff.
How do you prove that you didn't sexually assault someone 5 years ago? Gee, a recording of all of your interactions would come in handy here.
[1] http://injury.findlaw.com/torts-and-personal-injuries/elemen...
https://kristof.blogs.nytimes.com/2014/02/01/an-open-letter-...