Nurse Emma Randall knows how to talk a load of balls to teenage boys, but the aim is to educate them about testicular cancer.
It was an unenviable task - talking testicles with teenage boys with a rock band as your warm-up act. And it was the first time research nurse Emma Randall had given the presentation, advising them to fiddle with their bits on a regular basis.
After hearing an exuberant performance of "Sweet Home Alabama", the senior pupils of Northfield Academy in Aberdeen were in high spirits.
Several were wearing T-shirts with "Use a condom" emblazoned on their backs, and indeed one or two were already in use as balloons, floating across the school hall as Ms Randall took the floor.
But she was more than a match for them, rattling through her pitch with rapid-fire one-liners for the occasional jokers. If you're going to talk balls you have to have them, and tough-talking Ms Randall was rewarded with the respectful audience her subject deserved.
Her talk was part of a series of roadshows for schools in the north of Scotland organised by the Aberdeen-based charity UCAN. It campaigns to raise awareness of urological cancers affecting men - prostate, testicular and penile - and kidney and bladder ones which affect women too.
"Testicular cancer is the most common cancer among young men and can occur as early as 14," she told the senior Aberdeen pupils. "The sooner you detect these cancers, the earlier you can diagnose and successfully treat them."
Girls in the audience were told they could play their part by passing information on to their brothers, dads and boyfriends. "It is a highly successful treatment if diagnosed early," she told them.
The charity was taking part in a health information day at the academy, where outside agencies were invited to give youngsters information about subjects ranging from sexually transmitted diseases to alcohol awareness.
Since its campaign began, UCAN has used directness and humour to dispel embarrassment and communicate information about potentially life-threatening conditions. Around 50,000 plums were distributed early in their campaign, and people wore underpants over their clothes for a sponsored walk in the autumn
Ms Randall said testicular cancer affects men between the ages of 14 and 44. "The most common symptom is a painless lump within the testicles," she said.
"You could also have a dull ache in the abdomen or in the groin area, and you could also have enlargement of the testicles. But the most common one is the painless lump.
"So how do you detect these lumps? If they are painless, you are not going to know about them unless you have a good feel. And this is the best way to detect testicular cancer - self-examination."
She added: "We recommend that you do it once every month, which shouldn't be hard going, asking you all to have a good fiddle down there." The boys in particular seemed to be enjoying this talk and they were certainly listening.
As well as self-examination, Ms Randall said pupils should pay attention to their diet, cut out smoking and get regular exercise. She warned them that smoking is the number one preventable cause of cancer and that diet is responsible for 30 per cent of all cancers in western Europe.
Backed by the band Estrella, UCAN has already taken its roadshow to a dozen schools throughout the north of Scotland.
Sixteen-year-old Scott Arnot said: "I was shocked at what I learnt about the cancer. I knew it existed but I thought it was something that happened to other people, not someone like me."
Another fifth-form pupil, Leighann Urquhart, said: "It was interesting because some boys are not aware of it and I am sure now they will pass the information on."
Kate Synott, UCAN's fund-raising manager, said: "The best thing about it for the kids is that it starts to reduce the stigma right away.
"If they are learning at the ages of 14 to 17 that it's all right to be examining yourself and talking about testicular cancer, they are never going to get to the stage where the stigma takes over by the time they've got a problem.
"It's essential to reach this age group because this cancer is becoming more prevalent and it's starting in younger kids. So if they are aware that there are likely problems or they know what to look out for, then the earlier they identify the better. Nine out of 10 cases, if they are identified early, can be treated successfully."