Curious what folks like to do with spent coffee grounds / espresso pucks / stale beans. Personally have tried to use as fertilizer with limited success, used as a substrate for growing oyster mushrooms, and in cooking (brown bread made with some stale espresso grind really helps the flavor).
Like most commenters, I throw them with the filters on the compost pile. But recently I had a dog in the neighborhood pulling out plants in my front garden, and shitting in it. Spreading some of the coffee grounds seemed very effective against that too. I guess the dog doesn’t like the smell. So it;'s a win-win because the plants profit from it directly too :D