How to keep a shared kitchen actually clean
Make cleanup part of cooking: rinse and load dishes, wipe counters, clear food, and empty the sink. A kitchen stays clean when each person ends their own task.
Set a rotation for the work no one owns: floors, refrigerator, microwave, trash area, and shared shelves. Make the standard specific enough to see, not vague enough to debate.
When someone misses a task, speak directly and calmly. The goal is a reset, not a record of faults.