Dishwashing is a daily household chore that significantly impacts resource consumption, including water and energy, depending on individual habits. Understanding consumer behavior is essential for effective resource savings in domestic settings. This research aims to enhance knowledge of global manual dishwashing habits through a laboratory study comparing resource use and cleaning results between manual and automatic dishwashing. A consumer panel from 29 countries participated, washing twelve soiled place settings based on international and local standards. The study considered country-specific factors such as tableware, food residues, and dishwashing utensils. Resource consumption data was collected, and cleaning results were visually assessed. Consumer habits and attitudes were documented through questionnaires and video observations. Additionally, six country-specific dishwasher models were tested across three programs using the same soiled samples. The findings indicate that automatic dishwashing optimizes the process, achieving up to 87% savings in water usage per item and up to 58% in energy consumption, with cleaning results improved by up to 36%. The questionnaire highlighted varying attitudes towards manual and automatic dishwashing across countries, revealing a general lack of awareness about the advantages of automatic methods. Notably, washing in a filled sink emerged as the most resource-efficient manual practice
