"Basically, in life, rule of thumb: if you don't absolutely have to clean anything, don't clean it."
Fashion designer Stella McCartney said this in an interview with the Observer this weekend, adding that she picked up the tip while working for bespoke tailors on London's prestigious Savile Row. Instead, she says, the "rule" is to "let the dirt dry and you brush it off".
So does she have a point? Is it better to avoid washing your clothes?
Killing the planet one microfibre at a time 洗衣服脱落的微纤维正在一点一点地毁灭地球
Photo by Marco Secchi on Unsplash
This isn't the first time McCartney has recommended not washing our clothes. In fact, she has long advocated avoiding the washing machine - both for the longevity of the garments, but also because of the impact washing them has on the environment.
Laura Diáz Sánchez, from the Plastic Soup Foundation advocacy group, agrees with this, particularly when it comes to high-street clothes, which contain more synthetic materials such as polyester and acrylic.
"Every time we wash our clothes an average of nine million [plastic] microfibres are released into the environment," she tells BBC News. "The way we wash our clothes affects this, as well as the way our clothes are made - but the more we wash our clothes, the more microfibres are released."
When you do wash, she recommends setting the machine to a lower temperature and using liquid detergent: "Powder detergent creates more friction between the clothes [during washing], so more fibres are released, whereas liquid is smoother. The less friction there is in general, the fewer fibres are released."
Prof Andrew Groves, head of the fashion design course at the University of Westminster, tells BBC News that the friction in washing machines is what gets rid of the stains, but is also what distorts a garment's shape and color.
"I have garments in my wardrobe that I've had for decades that look brand new, simply because I know how to care for them," he says - adding that this goes for both high-end and high-street pieces. The better you look after your clothes, he says, the longer they last, and the more sustainable your fashion is.
"Machine washing can destroy things like delicate lace or silks," she says. "It can also make the wires pop out, it can make the colors fade, and if it's got a moulded cup it can make it go all misshapen."
If you absolutely must machine wash, she adds: "Always do up the hook and eyes to stop any snagging, use a lingerie bag, don't wash with too much heat, and reshape when it's out and hang it to dry or lie it on a flat surface."
Sarah Clayton, head of the Love Your Clothes campaign by environmental charity Wrap, also suggests not washing your jeans, but airing them between wears instead: "If they have a stain you could try spot-cleaning them with water rather than washing the whole garment."
Prof Groves agrees with Mr Bergh, and recommends sticking jeans in the freezer in order to kill germs instead.
"Most people I know, when it comes to their denim, don't wash it at all," he says. "Which might seem strange - it's a pair of jeans that they might wear every day. But it's usually because they don't want the color to fade."