Ayna Garayeva, a schoolteacher in the capital of authoritarian and secretive Turkmenistan, began taking extra sanitary measures in her classroom when the government issued new guidelines in August.

As well as standard coronavirus precautions like temperature checks for students, she started fumigating her classroom with the smoke of a herb beloved by the ex-Soviet country's leader.

"We are following the instructions as they are laid out," 42-year-old Garayeva told AFP.

In tightly controlled Turkmenistan, which still insists it has no virus cases, the pandemic has led to a boom in a herb whose Turkmen name translates as "medicine for a hundred illnesses".

Wild rue -- known locally as yuzerlik -- has for millennia been popular in North Africa, the Middle East and Central Asia as a panacea for sickness and ill fortune.

But in Turkmenistan, strongman leader and ex-dentist Gurbanguly Berdymukhamedov has gone a step further.  

In March, he ordered wild rue burning on a "systematic level", trumpeting the bacteria and infection-killing qualities of its faintly intoxicating smoke.

At the same time, authorities continued to hold ostentatious mass events and deter citizens from wearing masks.

Since the diktat, the cost of a wild rue bundle has grown five-fold to five manats ($1.43).

In neighbouring Uzbekistan, top sanitary doctor Bakhrom Almatov cautioned the herb has "no direct effect" on viruses, despite having healthy properties.

"After use, many people start sneezing. When they sneeze, the body expels dust that has fallen into it," Almatov told local media.

- Locking down with zero cases -
The World Health Organization declined to comment on wild rue specifically, but said traditional medicine in many countries "is often an important health resource with many applications".

Berdymukhamedov joins the leader of Madagascar, who gained notoriety for promoting a scientifically unproven herbal virus remedy at home and abroad. 

Herbal remedies have been widely used during the pandemic in countries with struggling public health systems, like Yemen and Sierra Leone.

Yet Berdymukhamedov's approach to the pandemic changed after the WHO visited in July. 

The delegation stopped short of dismissing his boast that that country had zero cases, a claim now only shared by North Korea and a handful of island states. 

But it recommended that Turkmenistan adopt measures as if the virus "were already circulating".

WHO Europe chief Hans Kluge tweeted weeks later that the group had "expressed serious concern about (a rise) in #COVID19 negative pneumonia" in Turkmenistan during a teleconference with Berdymukhamedov. 

Kluge said Berdymukhamedov had agreed to allow the WHO to sample virus tests "in-country" and send them to WHO labs for analysis. 

Since the July visit, non-food shops and restaurants across the desert republic have been shuttered. A ban on passenger trains and cross-country bus travel has been extended into next year. 

A mask-wearing regime was put in place in the summer to counter "dust" and unspecified "pathogens". 

Turkmenistan has yet to cooperate with the WHO's request for confirmatory testing, however. 

- Mutant-green sanitiser -
The WHO told AFP that the request has proven impossible to facilitate due to "travel restrictions".

Turkmenistan has indeed paused inbound flights, but state media last month said several German doctors unaffiliated with the WHO visited Ashgabat to meet with Berdymukhamedov and receive state awards.

Berdymukhamedov's instructions for fumigation are typical of his championing of indigenous fauna and flora. 

The all-powerful leader has also feted a national horse breed and a local shepherd dog in statues and various books he reportedly penned. 

His wild rue drive has caused a rare spurt in innovation in an economy dominated by the state and crushed by a six-year depression in energy prices. 

An AFP correspondent this month visited a trade exhibition where a state-owned company demonstrated new, cigar-shaped briquettes of dried rue that can smoulder for up to 45 minutes.

At 10 manats for six blocks, "they should be affordable to the local population," said a representative, who did not introduce himself.

At an exhibition in October, a representative of the private company Tach, who wished to remain anonymous, showed AFP an alcohol-based sanitiser with a mutant green hue resulting from a wild rue infusion. 

The sanitiser, which claims to kill "99.9 percent of bacteria" is yet to go on sale in pharmacies.