dishwasher:
(plural: ‘dishwashers‘; pronunciation: ‘dish…washer’)
a person who cleans/washes dishes, such as kitchen utensils, plates, cups, spoons, forks, etc., especially a person who works at a restaurant washing dishes,

a human dishwasher at work
Danny is working as a part-time dishwasher at a small restaurant to earn some money to pay for his hotel management course.
Most of the restaurants these days install automatic dish washing machines that do most of the dish washing; however, there are some restaurants that employ human dishwashers to clean certain dishes, plates and cutlery that need special cleaning technique that may not be possible in a machine.
As more and more chemicals and strong detergents are being used in cleaning jobs, dishwashers are required to wear protective gear such as gloves, eye-shades, plastic aprons, etc. to protect themselves from the dangerous effects of these chemicals.
Strangely enough in this particular field of dish washing, studies have shown that in Europe human dishwashers use much more water than the automated dishwashers!

an automatic dishwasher
For an illustrious article that explains how a mechanical dishwasher works,
please click here
&
please click here.
