What can I do about the office kitchen pigs?

I’ve found nothing works. Ever!

Confiscate all crockery and cutlery from the kitchen. Have a kettle, microwave, sink and dishwashing liquid. That way people can bring their own stuff, and if it’s left in the kitchen dirty it gets put in the bin. Even if there’s a designated person to clean up, all they have to do is put unattended crockery in the bin, wipe the bench and occasionally clean the microwave.