Almost a fifth of Britons living in the South East are likely to wash just four times or less per week, according to new research by academics at the Universities of Manchester, Edinburgh, Lancaster and Southampton.
However, less frequent bathing or showering, which is much more likely to be a habit of older people, may be dying out with huge implications, say the team, on the demand for water and energy consumption.
According to their analysis of 1,802 survey respondents, daily showering is now dominating bathroom habits, replacing bathing and flannel washing as a way to get clean.
Bathing, they say, is almost extinct as a way to dislodge the dirt: people have baths often only when there's no shower unit available to use, or when it is part of a pampering and relaxation routine.
And gone are the days of the flannel wash, something now practiced by only 29% of respondents, and which is now usually complementary, rather than an alternative, to a bath or shower.
Dr Alison Browne, who is based at The University of Manchester's Sustainable Consumption Institute, said: "These changes in bathing habits have potentially huge implications for water and energy consumption if these trends continue.
"Our findings that nowadays, nearly three quarters of respondents have at least one bath or shower every day, means both policy makers and society as a whole really need to think about what it means to be clean.
"As a society, we seem to be heading down a path of hyper-cleanliness."
Two of the six groups identified by the researchers, 'Low Frequency Showering' and 'Low Frequency Bathing' made up 12 per cent and 7 per cent of the population respectively.
The infrequent washes are likely to echo an era from generations gone by, where daily bathing was not common, or we may have washed at a washstand daily rather than fully immersing ourselves in water.
She added: "If the trend for more than once daily showering takes hold across the rest of the population, this not only has serious implications for energy and water sustainability, but it may also have a wider range of health impacts too.
"It's obviously really important to wash our hands after using the bathroom or sneezing to stop the spread of bugs.
"However, scientists are increasingly saying our hygiene obsession has adversely impacted on health, especially autoimmune and other related diseases.
"Unfortunately, it does seem likely that these infrequent patterns of practice are not being transmitted to younger people, and there is a risk that they may disappear altogether or are being taken over by much more water intensive norms."
Two groups, of about 15 per cent each of the total, tend to be young and active, often having more than a daily shower.
The 'Out and About Showering' group take showers or baths more than once daily, including showers outside the home, particularly at the gym, while 'Attentive Cleaners', who seem to enjoy the bathing experience itself, also have eight or more showers or baths per week."
Of the groups identified in the study, 'Simple Daily Showering' was the largest, performed by almost 40% of the population.
Most of this group showered every day, at home, seemingly something performed out of habit as the accepted, and most convenient, way to stay clean and fresh.
Women in the 'Out and About Showering' group are more likely to shave their legs and arms – though there are more men than women in the group overall.
Both male and female 'Attentive cleaners' are substantially more likely to shave their body, particularly under arms and legs for men: 41 and 22% do, respectively, compared to 17 and 13% in the rest of the population.
A final group: 'High Frequency Bathing' is characterised by a mostly daily bath, but almost never a shower.
The High Frequency Bathing group is more likely to be less affluent than average, unemployed, and to be renting – which may mean that showering is not available to them.
"Patterns of practice: A reflection on the development of quantitative/mixed methodologies capturing everday life related to water consumption in the UK." Browne, A.L., Pullinger, M., Medd, W., & Anderson, BInternational Journal of Social Research Methodology. 2014;17(1):27-43.