F*CK IT. I'm a dermatologist, and I'm done watching you hide your back.

Let me tell you what I actually see. Not the spots. The life people build around them.

It's the invite that makes your stomach drop. A pool party. A beach. A hot tub. A friend shouting "let's all just jump in". Before you've even replied you're doing the maths: which top covers it, whether the water's "too cold", whether you can say you've just eaten. So you sit on the edge in a soaked T-shirt, pretending that's a choice.

It's the dress. You know the one. You saw it, you loved it, you tried it on, you felt incredible for about four seconds, and then you turned round to the mirror. It's still in the wardrobe. The tag's still on. Every party season you take it out, hold it up against yourself, and put it back.

It's the changing room, turning to face the wall to get your top off. It's long hair left down in the heat to cover your shoulders. It's the cardigan in July. It's the date you quietly cancel, in case it gets as far as taking your top off. It's a new partner's hand sliding across your back, and your whole body going rigid, waiting for them to notice.

It's the mirror, every single morning, before you've even had a coffee: twisting, craning, checking, getting dressed around the part you can't stand. You know exactly what your back looks like, because you've studied it for years.

And then there's the part that cuts deepest. Somebody, usually someone who has never had it, tells you to wash more. Wash more. As if you hadn't thought of that. As if you aren't already showering once, sometimes twice a day, never rewearing a top, changing your sheets every week, jumping in the shower straight after the gym and scrubbing until it hurts. Some of you have become so obsessive about hygiene that it's its own kind of misery.

You've spent a fortune. £10 on the wash someone swore by. £15 on the next one. The spray, the pads, the scrub, the patches, the dandruff shampoo that's now living on your shower shelf and being used on your back. Maybe a GP waiting list. Maybe £150 to £350 for a private appointment, and a new cream at the end of it.

Some of you are in real pain, with spots deep enough that you can't lie down on your back at night. Some of you have been at this for nine years or more, through antibiotics and retinoids and daily benzoyl peroxide, and you've honestly run out of ideas. Some of you lie awake counting the weeks to the holiday you've booked, the wedding, the one week of the year you wanted to feel good in your own skin.

And nobody says out loud how lonely it is. You can't ask anyone to look. You can't ask anyone to help. So you get on with it alone, in a bathroom, with your arm bent behind you at an angle your shoulder was never built for, a wash you can't reach, and a small voice asking what's wrong with you.

Nothing. Nothing is wrong with you. Hold on to that, because I'm about to explain why.

Now I'm going to ask you something, and I want an honest answer.

When you wash your arms, you can see them. You can reach them. You do your legs, your stomach, your chest, your feet, behind your ears. Your face gets a wash made specially for it, twice a day.

Now think about the middle of your back. The strip between your shoulder blades, right where a hand lands when someone hugs you. When did you last properly wash it? Not let the shower run over it. Not flail at it with a flannel for four seconds. Actually wash it, with a wash, worked into the skin, left on, rinsed off.

For most people the honest answer is never. Or almost never.

Your hands reach your shoulders and the small of your back. That's it. In between is a strip of skin that has been left out of your routine for your entire life. Not because you're lazy. Not because you don't care. Because you physically cannot get there.

And that strip isn't a quiet corner. It's where the conditioner runs down and sits, because most of us wash our hair last. It's where sweat collects under a bag strap, a bra band or a sports top and just stays there. It's where dead skin and oil build up with nothing to shift them. It's one of the places on your body that most needs a good wash, and it's the place that gets one least.

Every other part of you gets a proper wash. Your back gets a splash.

That was my moment of clarity, and I want you to sit with it. The advice to wash more was never wrong because you weren't washing enough. It was wrong because it assumed you could reach.

I'm not going to pretend bacne has one cause. Hormones, genetics, sweat, friction and stress all play a part, and no towel changes your hormones. But anyone dealing with it has been doing so with one part of the routine missing, the part every other bit of your body gets without a second thought. Wash your whole back, every inch of it, the way you wash the rest of you. That's the whole point.

So I stopped telling people to wash more, and started asking a different question. How do you get a proper wash to a part of the body you can't reach?

The answer turned out to be almost embarrassingly simple. Not another bottle. Not a loofah on a stick. A long exfoliating towel: about a metre of woven nylon with a grip at each end.

Here's the whole routine. Hair first: shampoo, condition, rinse, clip it up. Body next, as normal. Then your back, last. Lather your usual shower gel on the towel, take one end in each hand and pull it across your shoulders, between your shoulder blades and right down to your waistband, the way you'd dry yourself after a swim. Side to side, then top to bottom.

Leave the lather on while you brush your teeth. Rinse with lukewarm water. Hang the towel up to dry. That's it.

Sixty seconds, and for probably the first time in your life, every inch of your back washed, by you, on your own. No contortions. No help. No asking anyone.

The texture does the rest. The woven nylon helps lift away dead skin, oil, sweat, product residue and the bacteria sitting on the surface, the stuff your hands and a flannel just slide over. One side is firmer, for rough, bumpy patches. The other is gentler, for the days your skin is angry. Light pressure is all it needs. Please don't scrub. I'd honestly rather you didn't.

I'll be straight with you, because you've been sold enough miracles. It's a washing tool, not a treatment, and it won't clear anything overnight. What it does is make a proper wash possible on the one part of your body that never got one. Expect a back that feels properly clean and smoother-feeling from the first shower. Anything beyond that takes weeks of a routine, which is why there's a 30-day guarantee.

Now picture the next time someone says "let's all get in". You don't do the maths. You don't check the mirror first. You take the top off, and you get in.