They literally will not do it at all. They refuse, and they will make me pick up the dishes and move them out of the sink.
Yes, if it were an add-on service, they would ask me for permission and then go ahead and charge me for the service. That is something they do with cleaning the oven and such other things. They simply will not wash dishes at all, period, full stop.
It's got to the point now, where if I forgot and left dishes in the sink, I will take them out and hide them somewhere, like the fridge, before the team arrives at my door. And then, hopefully I do not forget to retrieve them and properly clean them immediately.
I don't doubt the effect! I just wanted to point out that a domestic cleaning service does not require a license to do the dishes.