As a cricketer, reporter Michael Slater spent a lot of time in locker rooms, so he knows all about the overwhelming aroma of sweaty armpits BO. He sets out to find the best cure for BO.
What causes BO? Our body has two and a half million sweat glands and at rest in a normal environment, we produce half a litre of sweat per day. It's not actually our perspiration that smells; BO is created when sweat mixes with the bacteria that live on our bodies.
At Westmead Hospital, microbiologist Tom Olma takes a swab from a normal underarm. A few hours later he has a happy colony of breeding bacteria as a result.
"Bacteria basically are all over our body," he explains. "In some parts of our body they're warmer than other parts. Our body also acts as a form of nutrients, so the bacteria basically grow. As they grow they break down nutrients and they form volatile fatty acids that when released we can smell, which then creates an odour."
We all sweat and all have bacteria so how do we whack the whiff?
Players from the Gordon Rugby Club are going to help Michael with some sniff tests. Sheree Shepherdson is the nose who knows; our fragrant and impartial judge.
Four of the players are given four different types of deodorant. Four other players are not going to have any deodorant. Sheree will judge the results after the players have exercised.
Zane is given an antiperspirant spray. An antiperspirant contains aluminium salts. These both block and shrink your pores, stopping you sweating so the bacteria have nothing to feed on.
Todd is given a roll-on deodorant. Unlike an antiperspirant, a deodorant lets you sweat but neutralises the odour and has an antiseptic for the bacteria.
If you're anti-chemical there are natural alternatives like crystals. These are mineral salts which you wet before applying and they form a layer on the skin that stops the bacteria. Cam is given the crystals.
You can also make a homemade treatment by mixing up some baking soda and cornstarch. Add a few drops of essential oils and pat on. Mark is going to be the guinea pig for this one.
After the boys apply their different smell-repellers, Sheree does a pre-sweat sniff, giving each player a rating one is a very nice smell, 10 is an awful waft.
Zane gets a zero because Sheree can't smell anything. Cam gets a one; Mark receives a one rating too and Todd gets a two.
For comparison, four more guys won't be wearing any products ... and even before the game, they're a bit whiffy.
The boys are going to get good and sweaty with a 30-minute game of footy. Sheree will then get sniffing again to see which product has worked best.
No matter how hard the rugby players run during the game, they won't get as sweaty as Robin Levy. Robin rarely wears any garment with sleeves and has to change her clothes many times a day. Since puberty she's suffered from hyper hidrosis or excessive sweating. It's a condition that affects up to three percent of Australians; that's 600,000 people.
"Sweating for me is basically under my armpits and it becomes very embarrassing because they just get very wet and it limits the clothing I can wear," she says.
In her late teens Robin tried having her sweat glands surgically removed with little success. Now she's going to try Botox. It blocks the signals from the nerve endings to the glands and stops you sweating. It's not cheap at about $1500 a pop but Sydney plastic surgeon Steven Liew says there's no surgery involved and very little risk.
"Most patients will complain of some stinging discomfort, maybe a little bit of bruising and that's essentially it," he says.
First Dr Liew uses a combination of iodine and cornstarch to show up the areas where Robin sweats. He draws a grid to pinpoint where the Botox is to be injected and gets to work.
"In Robin's case we are going to use the entire ampoule, which is 100 units of Botox," says Dr Liew. "It's the standard amount we use for someone who sweat excessively."
Twenty minutes later it's all over. "It didn't really hurt at all," says Robin. "And for the success it's going to create, it's very tolerable."
Three weeks later, Robin's out shopping for a new wardrobe. Bring on the long sleeves for her, Botox has done the trick.
"I find myself checking myself under the arms all the time but I don't sweat at all, hardly at all," Robin reports.
As always talk to you doctor to see if this treatment is right for you, but Robin should be sweat-free for about eight months.
Sheree wishes it was the same for the rugby boys. They've been playing for 25 minutes and it's almost time for her to stick her nose back into those armpits.
Zane was given antiperspirant and before the match he scored a perfect zero for his pit pong (with zero being perfect smelling and 10 gross). Sheree gives Zane a two.
Cam got a rating of one first time around after using the natural crystals and Sheree gives him the same rating after the game.
Mark started on one with a homemade powder. Sheree gives him a two after her post-game sniff.
Todd began with a two and now receives a five rating from Sheree.
In our little test, the natural crystals came out on top with no change. Next was our homemade deodorant and then the shop-bought antiperspirant. The least effective was the roll-on deodorant.
Was wearing underarm protection better than wearing nothing at all like our other four players? Michael has jumped from a one to an eight, giving him the highest pong factor. Dave and Sam are rated six and Matt seven.
The lesson is that wearing any antiperspirant or deodorant is going to help keep that BO at bay. And the natural and home-grown stuff seems to work just as well as the chemical products. It seems to come down to what you're happy using.
Regardless of what roll-on, spray, crystal or homemade powder you use, the best and most efficient way to beat BO is to wash. Once a day, scrub clean it's as simple as that.
For women, shaving their armpits helps hygiene because the hair provides an even more fertile breeding ground for bacteria and a bigger surface area for moisture to cling to.
Young kids don't get BO but teenagers and adults do. This is because we're all born with some sweat glands but at puberty we develop another set called apocrine glands. These are concentrated in the armpits and groin, and they release stronger sweat, which odour-causing bacteria prefer.
We used the dry recipe on the show but you could try the liquid recipe as well.
To make a basic deodorant powder, use ½ cup of baking soda; ½ cup of corn starch, and a few drops of essential oils such as lavender or cinnamon, or try cedar and sage for men. Mix together and pat on.
For a basic liquid deodorant, use ¼ cup each witch hazel extract; aloe vera gel; mineral water; one teaspoon vegetable glycerin, and a few drops of antibacterial essential oils such as lavender or tea tree. Combine the ingredients. Shake.