What a crappy statement for your roommate to make.
I agree get some boxes, put them out of your sight and
put his dirty stuff in it.

If he continues with this attitude.....
As for dishes etc.
This might be a short term fix.
Paper plates might be a good idea.
Wash your stuff only.
leave his dirty dishes and let the stuff get caked on it.
Let's see how long he
likes to living in filth and having his other stuff piled up
in boxes till he takes care of it.

If it doesn't improve I would try to find another roomate
when the lease is up.