https://www.snopes.com/ra.showering-like-a-person/

^^ Yup as I said.

I guess we can set aside the issue of it not actually being a rat, and focus on whether it's "distressed" or not. If you go on rat forums (yep I went there) it seems that bathing rats with rat shampoo is quite common in the rat community (yep I went there), and if you look at other videos of rats being bathed in soap, they make similar washing motions as the creature in that video albeit mainly concentrated on the head and upper body. Then again, these other videos show rats soaped up in a basin of water - maybe they'd do the same thing if they were out of the water and completely covered in soap? 
 
So I guess the pertinent question is "is that pet shampoo"? 

Show me another video of a rat doing the same perhaps (pref not from teenage noodle ninja Nana's film).

 
Like I said, not to the same extent of Ratty McSoapface above, but you can see the similarities. 
 

 
I'll see you down in the sewer ...