SEATTLE • Mr William Ward sells a lot of chewing gum. He works at a newspaper stand just around the corner from a bizarre attraction called the "Gum Wall" near Pike Place Market, and people show up unprepared.

He also sells a lot of hand sanitiser. "I tell people it is the second-most disgusting tourist attraction in the world," Mr Ward, 31, said.

In his view, only the Blarney Stone in Ireland - which is said to give whoever kisses it the gift of gab, and which millions of tourists actually kiss - can top the gum wall on the gross-out scale.

But chewing gum, in a dozen or so varieties, still flies off the shelves. In most cases, he said, the gum is destined for only the briefest of chews before it is deposited, usually with a photo, on the wall, making it the city's strangest destination.

Now, however, the chewing gum is coming down after accumulating for 20 years in a deeply encrusted pointillist display of perhaps one million pieces.

All in, there is about 997kg of sugary, cavity-inducing stuff on the wall that Pike Place Market officials say threatens the integrity of the 115-year-old brick structure.

Crews on Tuesday morning started to remove the gum with garden rakes and superheated water of over 120 deg C in a three-day display of industrial-strength dental hygiene.

In the days before the cleaning, there was a rush of last-minute visits and gum-themed selfies. People, like the Fergus family from Phoenix, even stopped at Costco before leaving home to load up on supplies.

"Five packs, 15 sticks in each," said Mrs Christie Fergus, a pharmacist.

She and her husband Brian, and their two children, Michael, 8, and Rachel, three, chewed their way through the lot at the wall on Monday afternoon, then spelled the family's name in large bright green spearmint.

"It was pretty disgusting, but also a really interesting and fun family activity," said Mrs Fergus.

Michael, she said, gets credit for the family name idea.

Pike Place Market officials tried to protect the wall from gum after it began appearing in the 1990s, added by people waiting to enter an improvisational comedy club.

However, after several cleanings, and the realisation that mentions of the wall in tourist guidebooks like Frommer's were spurring people on, they surrendered.

A spokesman for the market, Ms Emily Crawford, said she expected that people would resume the practice the moment the wall was once again blank.

"It is a crowdsourced piece of public art," she said. "We don't need to promote it."

Mr Chris Borgen, 31, a firefighter from a Seattle suburb who had never visited before, said he was prompted to see it by his mother, who told him about the cleaning. He was there on Monday, holding up his son, Abbott, who is almost two, for photos.

Mr Borgen said he imagined coming back for a kind of time-lapse series, as the gum gradually comes back and Abbott grows up.

Thanks to the scale of their gum deposit, and perhaps the gross-out factor as well, Mrs Fergus said the family's visit to the wall had just about exhausted their desire for chewing gum.

"I think we will take a break from chewing gum for a while after that."

NEW YORK TIMES