I used to use the Finish tablets but they were expensive so changed over to Morning Fresh powder and haven't noticed a difference. I have never used a rinse aid and everything comes out spotless, no streaks or film.
I don't rinse anything before I put it in there. I know that everything will come out clean so I can't bring myself to use anymore water.
I clean the machine every few months (or when I remember) just with one of those Finish bottles that you put in the cutlery basket and that seems to do the trick to get it smelling and looking fresh again.