WDT970SAKZ3
With my WDT970SAKZ3, there is one prewash before the main wash, so I add a little powder onto the door when filling the cup. My feeling is that it will cut the grease a bit, and allow the main wash to be more effective.
And while we are on the subject of dishwashers, I noted in some posts that you know names of the platforms. I admire this knowledge, and I always wonder the source of it Anyhow, my buddy and I have our own code to denote each pump platform, mostly for Whirlpool. Going from most current backwards:
Square pump (like my WDT970SAKZ3)
Strainer style dishwasher
Blade style (with blade/strainer disk)
Spaceship (with the blade and seals that need a tool to press in)
Have I missed any?