The weeks before Christmas are always the busiest for Alexandria chimney sweep Vytis Grinius, and not just because winter is coming.

"We've got to clear the way for Santa Claus," said Grinius, covered with soot from top hat to toe yesterday. "The kids are fascinated with how it works. If you look up from the fireplace, you can see there is only a hole about eight inches wide. They want to know how he gets in."

As Grinius and his Chim-Chimney Chimney Service crew cleaned the way for Santa at Stanley Sherman's Gaithersburg home yesterday, two 5-year-olds watched the sweeps at work on the roof.

Parker Evans eyed the narrow chimney stack and shook his head. "He looks too fat to fit in," Parker said of Santa, "but he has to come in that way because our doors are locked at night."

"I bet he makes one of his elves go down," said Parker's friend, Christopher Krawiec. "Yep, maybe a real little one."

There are 58 million chimneys in the United States, plenty to keep Santa busy during the flue season, according to John Bittner, executive director of the National Chimney Sweep Guild in Olney.

"It's the busiest time of the year, my dear," sang Bittner. "While Santa and his trolls" still are making toys at the North Pole, he said, "the chimney sweeps of America are creating clean, easy access for him."

But Daniel Cline, a Bethesda sweep, puts a damper on the folklore of Santa's slide down the chimney.

"No. 1, Santa Claus is big and fat, and his dimensions -- let's say he's two feet wide -- just won't fit," Cline said.

"No. 2, It's too hot in the chimney.

"No. 3, 30 percent of all chimneys have a bend in them. The flue bends around like a question mark. And there is no way Santa could have a straight vertical drop. He would get caught and you'd never find him unless you burned something in the fire and noticed the smoke wouldn't go up like it should."

And, Cline said, that's not even mentioning the fact that most people keep their dampers closed to keep out the cold.

"If people would leave their door open for Santa, he'd really have an easier time," the Bethesda sweep said. "I think really the only way he could get down a chimney is if he found a large one, sucked in his stomach and cut the hole wider with a blow torch."

During the fireplace season, which starts in October, chimney sweeps not only clean out the creosote (the black sticky byproduct of burning firewood) for safety reasons, but also serve as good luck charms and Santa's advance men, according to folklore.

As the superstition goes, good fortune will come to anyone who touches the sooty sleeve of a sweep, or when, seeing a sweep at a distance, touches a button and makes a wish.

"Parents have had their kids touch my hand," said District chimney sweep Carlton Poles. "I guess you'd say I do have good luck, because in 20 years of climbing chimneys, I've never once fallen."

Dick Van Dyke popularized the good luck notion in the 1964 movie "Mary Poppins," as he sang:

Chim chiminey, chim chiminey,

Chim chim cheree,

A sweep is as lucky as lucky can be.

Chim chiminey, chim chiminey,

Chim chim cheroo

Good luck will rub off

When I rub hands with you.

As Christopher Krawiec stared up at the Gaithersburg chimney and further pondered Santa's delivery hassles, he decided that maybe instead of an elf sliding down the chimney, Santa has a "special secret way" that he doesn't tell anyone.

Grinius said a lot of kids are too smart to think a plump man with a sack of presents could fit in a narrow chimney. "So what do I tell them? I tell them Santa has magic dust that takes care of everything," he said.