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).
Paper filters and grounds go directly into the compost bin. We dont have municipal so I have to pay for a compost service but its 100% worth the $40/m to not have a smelly trash can.