On first hearing of the Glacial Shells Detox Massage, my first thought was that there aren't any freezers big enough to chill the giant calcified chunks needed to pummel my shadowy husk of a person to a satisfying conclusion.
However, this treatment doesn't actually involve squishing your body with below-zero fossils dug from glaciers to squeeze out any nasty toxins. It's far more subtle than that.
It's all to do with using hot lava shells applied under pressure on the body, then similarly using ones that have been sat in ice straight after.
So, happy that I won't be flattened with a frozen mollusc carapace or four for no reason, I trot along to the famed Sanctuary Spa in Covent Garden (my first time there, despite using their divine products for years) to let therapist Berenice (or is that Beren-ICE?) do her chilly (and toasty hot) worst.
The treatment is billed as helping get rid of cellulite, increasing blood flow in the torso, legs and skin, increasing lymphatic drainage and sorting any abdominal issues. Although not a deep tissue massage, it is still great at ironing out stiff muscles and niggles too - once you get over the shock of having red hot shells followed by ice-cold ones used on your body.
It follows the age-old Scandi idea of a sauna followed by a plunge into an ice-pool. There is scientific reason in the hot/cold schtick too as it shocks both skin, fat and underlying muscle cells into regenerating and helps circulation. Physios that I've seen before over the years have often recommended hot/cold treatment for various aches, pains and injuries so the science is sound.
Promising a de-bloated tummy and orange-peel-free pins too after a few sessions (six is recommended as a minimum), it's billed as a good start for your beach-ready body. It's also described as helpful for pain relief from menstrual cramps, bloatedness and to relieve the symptoms of Irritable Bowel Syndrome.
It's also supposed to help with any aches and pains, and as someone suffering from arthritis in the spine, as well as two prolapsed discs and sciatica, Berenice says she'll target muscular trigger points for that too (she does and it feels sublime).
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So what happens? After being led through the labyrinthine Covent Garden Sanctuary Spa to the relevant room, Berenice makes me comfortable. You can leave your top on if you like, bonus for the more bashful, but best get down to your scants.
Berenice then gets to work with alternately freezing cold and hot shells, which are actually made of porcelain, used in a firm, deliberate rhythm on your legs, arms, back and torso. It's almost uncomfortable at times, as it's not something most British bodies are used to, but it's really, really pleasurable once you get over the odd feeling. It feels like the warmth of the hot shells penetrates deeper through your body as a result.
The deep belly massage feels weird too, targeted onto the intestines to move the flow along, as this is not usually a part of the body that gets any attention. It seems to work though, as within a minute, my guts are gurgling embarrassingly - it must be doing the trick!
If you had a bag of frozen peas and a pain-relief wheat bag that you heat in the microwave, you could attempt this yourself (I have both, due to being old) but you would have NOTHING on Berenice. This lady really is a master of hot/cold massage. Besides, you'd never manage to reach the places she can on your own or have the knowledge or skills to target the areas that she does.
Afterwards, my legs feel ridiculously light and I actually skip down the street to get the Tube to work.
The feeling continues all day and I feel like I'm walking on air. As to the reduction of cellulite, well, there's a lot of work to do, but I can imagine it having some effect after six.
I only wish I had the cash to buy another five sessions. This treatment is hot (and cold!) stuff.
Glacial Shells Detox Treatment, 55 minutes costs £85. Sanctuary Spa, Covent Garden, London. To make a reservation call 0845 521 4567or visit the website.