First, we typically dump out as many grouds as possible into the trash/compost (side note: try this gardening trick!). A couple quick upside-down vertical shakes and that's that. Then we typically rinse the grounds off the walls of the filter by running the faucet along the outer walls of the filter. Then, we run the faucet inside the filter, and what you'll notice is that a pool of water will collect in the bottom before it quickly drains out through the walls. So we basically take advantage of this temporary pooling effect by doing a series of rapid fill-and-swirl-then-dump-upside-down maneuvers one after the other. We personally don't mind a couple stray grounds left in our filter, but if you do enough of these maneuvers, you can definitely get all of them out! To see it in action, check out this Instagram video.