There is a certain satisfaction in learning the stories of people who, through luck, circumstance or sheer grit, have ended up in precisely the right job. Australian director Lachlan McLeod’s “Clean” turns out to be just such a story, but here the job is trauma cleaning — that is, swabbing down crime scenes and suicide sites, clearing out inherited or repossessed houses, assisting the mentally and physically disabled with home maintenance and tackling the grimly fascinating phenomenon that is hoarding. Initially it’s unfathomable that anyone’s life experience could make them ideally suited to this extraordinary, specialist profession — much less to develop an entire philosophy around it. But that’s before we get to know Sandra Pankhurst, the founder of Melbourne-based trauma cleaning company STC.

McLeod’s approach is at first a little coy, implying the film will be less about any one person than about the necessary but often harrowing services STC provides. But Sandra, a likable, frank, often foul-mouthed sixtysomething who doesn’t let her serious respiratory disorder (picked up on the job from inhaling toxic fluids as a rookie without adequate PPE) get in the way of a bawdy wisecrack, quickly emerges as the film’s magnetic core. And that’s before we’ve even glanced into her backstory (MacLeod shapes the narrative in a rather withholding way so that existing information can be played as revelation).

Gradually though, interspersed with segments about various jobs STC goes on and the effect they can have on STC employees, Sandra’s story emerges, and it is quite the rollercoaster. From an abusive childhood as an adoptee all but rejected by her parents after their biological children came along, to a failed first marriage and abandoned kids, to coming out as trans, to a troubled stint as a sex worker and drug user. By the time she founded her trauma cleaning business three decades ago, Sandra had already had plenty of experience in trauma.

That perspective gives her take on her sometimes grisly profession such a zealous, almost vocational aspect. Sandra is irreverent to the point of filthy when talking about herself (“The things that come out of my mouth!” she says at one point, quickly adding, “But I tell you what, you’d want to see the things that have gone into it”), but her language turns scrupulously professional and respectful when she’s talking about her work. The policy she preaches — quite literally, since embarking on a public-speaking career in the wake of a bestselling book based on her life — is one of empathy, kindness and refusal to pass judgment on the messes she’s hired to clean up.

It’s an ethos shared by her staff, who’ve run the operation without her on site ever since she was forbidden by her doctors from attending the cleans anymore. Several of them are interviewed while at work, cheerfully comparing the delicate work of sorting through debris for used syringes to the game of pick-up sticks, or assessing the time it will take to clear a “level-9 hoarding” situation in a deceased man’s house. “I think we are all one or two bad decisions away from living this exact same life,” says STC staffer Rod Wyatt as he surveys a barely livable sitting room filled with decades’ worth of damp newspapers, before revealing his own history as a hoarder.

As with many forthright people, Pankhurst’s no-nonsense personality serves to protect as much it projects, rather like the perfect mask of make-up that she is often shown carefully applying. Extrovert though she can seem, Pankhurst is also very private, and “Clean” does not presume to pry where she does not want it to. So while her decision to try, after all this time, to contact her birth mother becomes a story strand that is foregrounded, there is little mention of her own children, now adults, until a hurried postscript. For all she cares to reveal — and this is a woman who casually drops the “salacious” bombshell that she has just been diagnosed with a brain tumor five minutes before going for an onstage interview — there are some areas of her life that still appear too raw or too personal.

As though to fill in some of those gaps, MacLeod’s least successful gambit is the unnecessary historical re-creation of scenes from Sandra’s past, which along with the reconstructions of crime scenes pre-cleanup — shot in a doleful muted palette so the blood splatter on the wall or the reddened water trickling out of a bathtub really pops — are unnecessary at best, maudlin at worst. But despite such little missteps, and a parallel between physical trauma cleaning and mental trauma survival strategies that could be drawn tighter, “Clean” remains an engaging, spirited doc, designed less to provoke than to inspire. Like Pankhurst’s whole, remarkable life, it’s a testament to what can be achieved, and what can be overcome, with a combination of chemical cleansing agents and industrial-strength compassion.