I know you said this in jest, but I actually personally do try to not leave little pieces of food on my plate as it saves having to scrape it off later, but I've never even suggested to my wife that she do the same and even if my kids weren't only 3 and 5 years old, I don't think I'd bother asking them.
I’m so glad my wife and I are aligned on the manual rinse thing as I don’t think I could suffer silently. We’ve had enough silly disagreements about other things like how to properly load the dishwasher. After a few decades, she does it her way and I do it my way. The dishes come out clean for both of us so we both deal.
I think we both grew up in households that did full manual washes most of the time even though the dishwasher was there; it was reserved for special occasions like Thanksgiving or Christmas when there really was a lot of dishes.
But are you saying you force yourself to eat all your food, even if you are full or don’t like it, just to avoid scraping it into the trash bin?