After spending 8 days with the mess of making coffee in a Platy, and cleaning it out, and dealing with the grounds, I came up with this...
...a zipTop Platy and a NoSeeUm coffee bag.
Grounds go in the bag, bag goes in the Platy, add hot water, seal, and wait.
Pour off coffee and drink.
Remove coffee bag, let dry, shake out the grounds into the trash bag, and pack 'em out.