I have a roommate that things it's ok to not use soap when washing her dishes. 
I am constantly finding plates with food or grease still on them.
user
That is annoying!  Is someone in your house not doing there job cleaning after themselves.
assistant
No, they think they are but I guess they are lazy and don't use soap on their dishes or will just dust the plate off and put it in the drain! lol
user
That is no good.  What are you going to do about it?
assistant