washer-up 
noun (plural washers-up) British
A person whose job or task it is to wash the dishes and other utensils in a kitchen.The hotel's general manager said ‘Jeremy was booked in as a guest, and our regular washer-up was late.’...
- Make sure you recruit a washer-up at home before you start cooking, though - the argument being that all your time and creative energy will have been spent fine-tuning your new repertoire to perfection.
- I was working as a washer-up in an Indian restaurant in Stratford-Upon-Avon, back in 1985.