One of the most sought after spa treatments in London is not some fancy facial or sophisticated massage technique, but simply smearing yourself and your partner from head to toe in glorious mud.

My husband is not a big fan of spa treatments. He gets bored if he has to lie down on his own for too long. But when I suggested we have a Rasul mud bath together, he perked up — the idea of being locked away in a Moorish love chamber with me obviously pressed a romantic button.

The mud massage takes place in a steam room with burnt orange walls and Moroccan-style furnishings, leading into a blue-tiled temple with a dome of stars, like something out of the Arabian Nights. It is specially built for two and guaranteed to evoke warmth and passion in even the stiffest-lipped British male.

“It’s a primitive treatment,” says Noella Gabriel, director of product and treatment development, who devises all the treatments at the Elemis spa in London. “The Rasul experience is very childlike and playful, but it’s also powerful and great for detoxifying and muscular problems.”

It is a treatment that seems to appeal to several types including spa virgins. One couple in their thirties whom I met emerging said they did it regularly as a chance to just “chill” together, as they both worked such long hours. The fact that you can be in and out in under an hour means it also works as a lunchtime “quickie” or before going out to dinner.

There is no doubt that many will find the treatment a bit of a turn-on. After all, who has not fantasised about having a bit of nookie shut away in a public place? It is the fun element, how- ever, that seems to be the key to its success. “As a therapist, the lasting memory I have of the Rasul is of the sound of laughter,” Gabriel says. “Whether it be husband and wife, best friends or mother and daughter, all seem to have the same light-hearted experience.

“Although it is a deep- cleansing ritual of ancient origins, sitting there with your best friend or partner eventually leads everyone to laughter and this is the true value of the ritual. We have all got too serious about our visits to a spa.”

It certainly works on the laughter front. When my husband and I stripped off, took a shower (helps the muds absorb better) and then slipped on traditional cotton Balinese sarongs, my husband declared he felt like David Beckham.

Our therapist reappeared to lead us into the steam temple (did I detect a smirk?) where we could smell a delicious fusion of herbs — lemongrass, chamomile and lavender. There was a throne on either side (“Posh and Becks again,” whispered my husband) and four little pots of mud, or “medicinal earths”, that we were instructed to apply on specific parts of each other’s body. Sourced from Germany, the muds are packed with minerals, such as caolinite and montmorillonite, which draw out toxins. As they dry, you instinctively rub them, which exfoliates your skin leaving it silky smooth.

So in the privacy of our chamber, we abandoned our sarongs and smothered each other all over with the multi-coloured muds. One of the aims of the Rasul, Gabriel says, “is to offer couples a safe, intimate cocoon where they can catch up or chat”.

As the muds on our bodies slowly dried, we decided it would be more fun to snuggle up on one throne than sit opposite each other.

We were kissing and canoodling like teenagers when the lights suddenly were switched on and water poured down from above. The traces of mud washed all over the tiled floor as I returned to my own throne to ensure that we both got a good enough soaking to wash us clean.

Back in the entrance chamber, we were instructed to shower again to remove any remnants of mud. And this time we ran into the cubicle together like honeymooners rather than the exhausted married-for-12-years couple who had grunted hello to each other when we had arrived only an hour before.

WHERE TO ENJOY A TWOSOME

Tania Alexander and her husband tried the Rasul Experience for Two at Elemis as a Red Letter Days Experience, 0870 4429119; www.redletterdays.co.uk - cost: £99 for two people.

The Elemis Day Spa (2-3 Lancashire Court, London W1, 020-8909 5060; www.elemis.com) has a Time for Two Couples Ritual — one hour of treatments for both of you comprising a wellbeing back massage and an exotic frangipani body nourish float. A glass of champagne costs extra. Cost: £190 for two people.

The Sequoia Suite (Grove Hotel, Chandler’s Cross, Herts, 01923 296133; www.thegrove.co.uk), part of a luxurious spa, is specially built for couples or intimate friends with two treatment beds, a double shower and an ergonomically-designed, mosaic-tiled bath for two. A session includes an hour to unwind in the steam room, and a petal-strewn bath, followed by two hours of treatments of your choice. Cost: £400 for two people.

Nirvana Spa (Mole Road, Sindlesham, Berks, 0845 123 7575; www.nirvanaspa.co.uk) has a flotation pool where you can float together in Dead Sea salt water — 45 minutes in the pool is said to be equal to eight hours’ sleep. Cost: about £85 per person, includes flotation, lunch and refreshments

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