There's a new ad on the woman-hating block. It features a sad cartoon lady hiding behind a large plant pot. She is coaxed out by a perky-voiced woman exclaiming "You sweat! And no wonder!" Apparently the vaginal area contains more sweat glands than any other part of the body – who knew? Anyway, the voice continues, this odour is completely normal, so we shouldn't worry about it – except we should, because we need to buy this special wash to deal with it. After all, we wouldn't want to spend our time hiding behind giant plant pots, would we? Sad woman agrees, and, empowered by this new information, and no doubt keen to get off to her nearest stockist, she kicks over the plant pot in triumph. Viva Vagisil!

I first saw the ad this weekend, and it's been niggling away at me ever since. It's partly its insidiousness in presenting Vagisil as if they are on our side – no need to worry girls, this odour is completely normal! The thing is, if this supposed odour that causes grown women to play hide-and-seek is completely normal, there would be no need for a product to deal with it, would there? No. So what Vagisil does is pretend to be our friend, helping us deal with this smell that's been plaguing our social life; in reality they are manipulating us into thinking we stink in the first place.

Well, I think Vagisil stinks. And not just Vagisil – the world of advertising to women in general. Today, BBC Woman's Hour invited Gail Parminter of the ad agency Mad Women on to talk about a new study that has determined the time of the week when women are feeling most vulnerable (it's Monday morning, in case you were wondering). Armed with this knowledge, ad agencies can proceed to bombard us with products that can "empower" us at a price. Viva Vagisil!

Of course, this is no surprise. The point of advertising is to sell a product, so obviously they will want to know when we are at our most suggestible. It stinks, but so do I apparently, so who am I to judge? What I will judge, however, is Parminter's claim that "Advertising doesn't create a market, it will tap into the market."

Ah, the market. That mystical lone wolf, just floating around of its own volition, in no way influenced or shaped by outside forces. Except of course, that's not how markets work at all. Markets are a product of the culture in which they exist. And the culture in which both Parminter and Vagisil exist, is a culture in which women are routinely judged according to their appearance, to their femininity. And in that already existing environment, where women are used to being told that they're too fat, too old, too wrinkly, just too much in general, what could be simpler than to add another to the list, in the form of too smelly?

Vagisil's product doesn't just offend me on the basis that it is adding yet another paranoia to the long list carried around by the 21st century woman trying to survive in a system that teaches them to hate themselves. It offends me in the same way that Parminter's claim offended me: the dishonesty. Vagisil attacks and diminishes women's self-confidence, in order to sell it back to them at a profit – hiding behind a "we girls are in it together" mateyness. Parminter hides the complexity of the reciprocal relationship between advertising agencies and the markets they both reflect and create, in a glib formulation that is packaged up so prettily, we're meant to swallow it down whole.

Well, I'm sorry, but I'm not buying it. I'm not buying the idea that advertising agencies only try and fulfil our deep-seated desires, rather than creating them for us. I'm not buying the idea that women have always been concerned about their "intimate" odour and just longing for a product that solves this age-old problem. And most of all, I'm not buying Vagisil. Ever.