Hi Chloe
We were cleaning an office twice a week and I'm sure they didn't wash single mug in between! We were faced with 30 dirty mugs, manky soup bowls and dried up microwave meals every visit. It was disgusting and we always did it, but if we missed one bloomin skirting board they'd be whinging like mad!
When I was an office manager, our cleaners didn't wash up so I think we were just being taken for mugs lol
Cheers
Diane