CLEAR-headed Tony Taig has not had a cold for more than 10 years.

It's one of the benefits of having what may be the healthiest job in Australia.

His occupation is certainly one of the oldest.

As the fourth generation of his family to fire up the eucalyptus still at Arnold, about 50km west of Bendigo, blue eucy oil runs in his veins.

Oil seeps through the pores of his skin and his breath - Tony reeks of the Australian bush. "I might have had a flu or two over the years but never a cold I can remember, never ever," he said.

While other pioneers in this part of the world were stricken with gold fever, Tony's great grandmother, Anne McKean, chanced her arm at eucy oil.

The medicinal qualities of the dwarf native shrub were well-known to local Aborigines and the poorly provisioned European settlers soon learned of its medicinal magic.

In 1895, when the men were busy trying to hack out a sheep farm from the wilderness, great-grandma gathered armfuls of the teal blue eucy shrubs and stewed them up at home, probably in her copper.

Those drops of oil floating on top of the water would sustain her family for more than a century.

"It was very unusual for a woman in those days to start a business," Tony said.

Settlers in the area helped the family to vary their diet and to stock up on essentials through bartering.

Mrs McKean was able to produce something unique for the travelling salesmen who would negotiate the most treacherous roads in their carts and buggies.

Hold up a leaf to the sun and you will clearly see a pattern of veins. Do the same with a blue eucy leaf and you will also see tiny specks, trapped globules of oil.

The distinctive paddle-shaped leaf grows in central Victoria and very few other places, on shocking country.

At one time this thirsty soil in the Golden Triangle was also littered with gold nuggets.

The world's biggest nugget, the fabulous Welcome Stranger, was found only 20km away as the crow flies.

Even today, as Tony harvests the shrub, he is sure to have some prospectors armed with the latest electronic detectors beeping away behind him like birds gobbling insects behind a plough. "They don't find very much these days. It's been picked over and over," he said.

The real gold here now glows when backlit by the sun.

Tony can get technical about the rarity of the blue eucy - after all, it is his family business - and talks up the cineole, or the active ingredient of the oil.

But most Australians need little convincing of the many benefits of eucy oil. It's already in most Australian homes, whether as an insect repellent, antiseptic, cleaning product or to use on a pillow case or hanky during sickness (just a few drops will do).

However, more than two-thirds of the eucy oil used in Australia is imported from China. Just a handful of stills, like Tony's, still operate in the bush, but they produce what they claim is an oil four times more potent than the import.

Tony is sure his is the oldest surviving family working the eucy oil trade.

His grandfather, a sleeper cutter, took over the business part-time from the amazing Mrs McKean. Then Tony's father and uncle both gave away shearing in the 1950s, and largely built the factory that exists today.

It is still a simple business.

The same shrubs are harvested today, on private and public lease land, as have been harvested for a century. Tony mows the blue eucy down, and it is then shredded and fed back into a tractor-towed trailer.

The dwarf tree's bulbous roots remain intact, and every two years grow to be harvested again - as they have grown for more than a century.

Trailer-loads of sticks and leaves are poured into a specially modified semi-trailer which has a hinged lid.

That lid is tightened, steam pipes are fixed across the bottom of the trailer, and distillation begins through a maze of pipes before the oil is produced.

Heat for the steam is produced from an old boiler, which once saw service dehydrating food at Colac in World War II.

Recently the boiler fire escaped and almost burned down the whole operation.

"It is the first time we've ever had a fire. It was very windy ... it took me a while running around to find reception for my mobile so I could call triple zero," Tony said.

A few charred poles and an embarrassed grin are all that remain of the fire today.

The dried leaves, the by-product of this eco-friendly operation, is sought after for garden mulch.

Most of the oil goes into 200-litre drums which are sent to a manufacturing plant in Melbourne, where it is made into soaps, lollies, handwash and those familiar small bottles.

Tony plans to market his own products under his Bygum label and online through his new website, the Australian Eucalyptus Oil Company, which he will have up and operating soon.

He has also recently celebrated the arrival of a son, who he hopes might one day continue the family tradition.

"There's not fortunes to be made in this game but it's been a good living," he said.