Lourdes grotto © José Luiz Bernardes Ribeiro / CC-BY-SA-3.0, via Wikimedia CommonsLourdes is a very complicated place. In many ways it is the Glastonbury of France, in that the veils are so thin there that it's not surprising it's the most famous visionary town in the world. In Lourdes, when you close your eyes, the ease of meditation or prayer is startling. It is like jumping down into a river to reach the Goddess and being carried along towards her on a fast tide. In fact the element of water and its corresponding attributes of love, emotion, healing and rebirth flow through both the story of the visions and the experiences of people today. It allowed me on one special day to feel a really strong confirmation of my priestess role through the element of water, and the healing power of the Virgin.

Lourdes is, in fact, three different places. On the top of the hill above the River Gave is a very smart French town, with a Black Madonna in its spare and beautiful church and a really good market. Between the town and the Domaine – the Virgin's place – is a steep hill which is full of images of the Virgin from the heartbreakingly beautiful to the most dreadful sparkly tat, and lots of other stuff for pilgrims. The hill also has restaurants and bars where the food is shockingly bad for France, except, surprisingly, for the English-run cafe, where lovely pastries and really good tea is served. It always amazes me that the French - people who can produce wonderfully delicious and complicated food - can't make a decent cup of tea.

On the flat river plain are 32 acres where no-one is allowed to sell anything. The water is free, the candles are for a donation – but nobody checks – and the Baths have to be queued for, often for a very long time, but there is no payment.

In 2012 I went to Lourdes for a week with an old friend who was 85, to take her there for the last time. One afternoon I heard in the hospital where we were staying that helpers were needed in the Baths, and I went along to volunteer.

As I got to a large door into the female section, and thought about knocking, a woman came out and said, 'Are you here to help?' I said I was, though how she knew to speak English to me and picked me out from all the hundreds of women milling around I don't know, as I had never seen her before. 'Good,' she said, 'Come on,' and I followed my kind guardian angel through the door and upstairs.

She gave me a large apron to wear, which was hanging on a hook, and some excellent advice, much as you would expect from an angel.

'Do everything the chef says,' she said, 'Don't argue with them at all. Here attendants in the Baths have been doing things exactly one way, and one way only, every day for over a hundred and forty years. Follow me now and do what I do.'

The chefs, it turned out, weren't the cooks but were the French women in charge of each cubicle, where nine attendants and nine nervous pilgrims waited at any one time. There were 12 cubicles in all. One cubicle was reserved for the dying and the severely disabled, and only the most experienced attendants were assigned to it.

I followed her into an upstairs corridor where many women wearing the same aprons as ourselves were lined up. We all prayed together to the Virgin and were blessed by the woman in charge of everything, and assigned to our cubicles. In the confusion I lost my angel, and never did see her again.

My cubicle was number 7 and the chef was just lovely. She had very little English, however more than my French, but just enough to tell me for my first job I had to welcome the women in. I did so and then another helper would take one, show her to her place and then pick up a large blue curtain and hold it between them so that modesty was preserved. Once the woman had taken off all her clothes, the curtain was wrapped snugly around her as she sat waiting for her turn.

After a while the chef moved me from welcomer to curtain holder for the English speakers. It was the French and Italian custom for a mother and daughter to go into the Baths together. When I explained this to an English mother and adolescent daughter the expressions of horror on their faces were so funny we all laughed, with the French chef shrugging in amused exasperation.

As each woman went up the steps to the bath, a large white curtain, this time hung floor to ceiling across the whole width of the cubicle, was pulled back and they were taken through to the inner sanctum and the curtain pulled to behind them.

After a couple of hours, the chef told me to go behind the white curtain and work as one of the attendants. This was so lovely. Each woman stood at the top of the steps with a large bath in front of her, about half the size of the one in the Chalice Well in Glastonbury. The bath was full of terribly cold, natural spring water, from the spring discovered by Bernadette, with a statue of the Virgin at the end.

The blue curtain was taken off the woman and a damp and very cold white sheet was wrapped around, by two attendants, in the twinkling of an eye. She would then walk down into the water, be immersed by us who held onto her all the time, and then be helped to walk towards the Virgin's statue, praying and always, always crying, to kiss her feet. It was a great honour to be allowed to be part of it all, especially with the sick. I have never been in any place that felt so holy, so centred upon women, and so open to the Goddess in my whole life.

Two attendants would rinse and then wring out the sheet after each woman, and every movement we made and the help we gave was very strictly prescribed. It meant that as we knew exactly what to do, the women felt this and were given confidence and trusted us enough to give themselves wholly over to the process. There were very few that resisted being immersed into the water, but those that did were handed a large jug to pour the water over themselves.

At the end each woman would have the sheet removed and the blue curtain wrapped around them again, and led to the changing area. There were no towels, or anything to dry with. I really don't know why but everyone became completely dry when putting on their clothes – maybe it was the icy coldness of the water, or not.

At the end of the afternoon we had the chance to go into the Bath ourselves, assisted by our sister helpers. After our immersions, we said the Salve together, a prayer to the Virgin, holding hands in a circle. Then we kissed each other goodbye as if we were all the closest of friends, or as priestesses after taking part together in a beautiful ceremony.

For the whole afternoon I was conscious of being a priestess, there to help these women, to serving them in these Baths where they left behind in the terrible cold everything that weighed them down or held them back, and then felt washed and cleaned and healed.

This was a beautiful and unique day, one golden space in time and a privilege not to be forgotten. It confirmed to me that dedication of oneself to the Spirit is not in anyone's power to give, She will have whom She wills. Walking this path between the Goddess and the Church is difficult in the extreme, but the Spirit moves and the Goddess is to be found in very surprising places if one's heart is open and one's awareness is perceptive and alive.