Here is a new Yomtov anxiety, to add to cleaning the house for your relatives' approval, and agonising over just the right shul outfit. Is your kippah as clean as it should be?

Now the largest chain of independent dry-cleaners in London is offering a solution to the stress of grubby kippahs. It is offering to dry-clean them for free.

Julian Stone, founder of the American Dry Cleaning Company, says he expects a round 30,000 people to take up his offer on September 1.

And, he says, the more religious the wearer, the more at risk they are from the dirt it collects.

He said: "Cleaning, and indeed cleansing, is such a central theme of the High Holy-Days - especially Yom Kippur. That's when it occurred to me that no one I know has their kippah cleaned. So we thought we would offer the service free this year.

"Your scalp and hair expels stuff, using a kippah as a filter. The more religious you are, the more you wear it, so the more dirt it picks up."

Mr Stone, who did a trial run two years ago with tallit-cleaning service at the Temple Fortune branch, added: "We expect the surge to start when people return from their summer holidays in Israel and Marbella, and the community is reminded that the holidays are approaching."

Is there a bracha for such an occasion? We asked Rabbi Yitzchak Schochet of Mill Hill synagogue, who two years ago offered a prayer for England's World Cup team.

He said there is no prayer specifically for dry-cleaning, but suggested: "With these High Holy-Day clothes that I do clean, I pledge this one goal: as cleanliness is second to Godliness, I will also look to cleanse my soul."

He said: "Kippot rarely if ever need dry-cleaning. It's more the mind underneath that could use the occasional stain removal."

Manchester's Rabbi YY Rubinstein washes his kippur weekly. "There is never a dirty yarmulka on the Rubinstein head," he said.

"I have about eight yarmulkas, which I rotate on a weekly basis. They can get dirty and sweaty. I wash mine in the sink. I have even taken it into the shower with me by accident one more than one occasion."

Nonetheless, he congratulated Mr Stone's initiative. "Personally, it's the only way to get ahead. I think it's a lovely idea for those people who have exquisite and antique headwear, for those in need of special care."

Rabbi Avraham Pinter, a leader of the Charedi community, said: "A kippah is difficult to clean and it might be more economical to buy a new one. But a free dry-cleaning service sounds good to me. If I give them four, will they do my kapote [frock coat] too?"