Does Marissa do the grocery shopping? Tell her to stop buying apples.
Hah! If she does do most of the shopping, that's a pretty ingenious solution.
I was going to suggest that.
Marissa's husband can't remember to throw his apple cores in the trash? No more apples for Marissa's husband!
Love this solution. What I'd do is collect the cores, dry them, and string them onto a necklace which would be ceremoniously given to him. Or I might save them in little baggies and hide them in spots around the house that he frequently uses like under his pillow, on his partition of the medicine cabinet, in his lunchbox...
He would take it as the joke it was meant as, realize that it was important to me that he dispose of them, and knock it off. But that's just how the two of us operate.
Part of me wonders why, if she cleans the dishes, why she doesn't just put the core down the disposal with the rest of the dish scrapings, using a fork or spoon to nudge it. I mean, if this is how they typically dispose of remnants...to me it would be no biggie. But I understand the whole dynamic of asking something of a spouse and them being unwilling to change. That's difficult.