Low-denomination US bank notes change hands until they fall apart here in Africa, and the bills are routinely carried in underwear and shoes through crime-ridden slums.
Some have become almost too smelly to handle, so Zimbabweans have taken to putting their USD 1 bills through the spin cycle and hanging them up to dry with clothes pins alongside sheets and items of clothing.
It's the best solution - apart from rubber gloves or disinfectant wipes - in a continent where the US dollar has long been the currency of choice and where the lifespan of a dollar far exceeds what the US Federal Reserve intends.
Zimbabwe's coalition government officially declared the US dollar legal tender last year to eradicate world record inflation of billions of per cent in the local Zimbabwe dollar as the economy collapsed.
The US Federal Reserve destroys about 7,000 tons of worn-out money every year. It says the average USD 1 bill circulates in the United States for about 20 months - nowhere near its African life span of many years.
Larger denominations coming in through banks and formal import and export trade are less soiled.
But among Africa's poor, the USD 1, USD 2, USD 5 and USD 10 bills are the most sought after. Dirty USD 1 bills can remain in circulation at rural markets, bus parks and beer halls almost indefinitely, or at least until they finally disintegrate.
Still, banks and most businesses in Zimbabwe do not accept torn, Scotch-taped, scorched, defaced, exceptionally dirty or otherwise damaged US notes.
Zimbabweans say the US notes do best with gentle hand-washing in warm water. But at a laundry and dry cleaner in eastern Harare, a machine cycle does little harm either to the cotton-weave type of paper.
Locals say chemical "dry cleaning" is not recommended - it fades the color of the famed greenback.
Laundry worker Alex Mupondi said customers asked him to try machine-washing a selection of bills and the result impressed him.
But storekeeper Jackie Dube hasn't yet taken up advice of friends to cleanse the often damp and stinking US dollars she receives for the garments and cheap Chinese consumer goods she sells in Harare.
It's time-consuming, she says, adding that stinky, unhygienic bills are a problem.
"I get rid of the worst of the notes as soon as I can in change," she said
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