Wayne Jones donned a gas mask outside Montgomery County's Winston Churchill High School and began to pur an ungodly potion of water and caustic acid on a brick wall studded with graffiti.

"The only good thing about graffiti," Jones said, as his partner, Floyd Adams, stood by with a hose, "is that it proves kids know how to read and write and how to do it quickly. By tomorrow there's going to be as much writing on the wall as there is now."

Adams and Jones an embattled pair who stand at the vanguard of a more then $20,000-a-year effort by Montgomery County public schools to rid school facades of graffiti. Ever since last winter when they succeeded two other school maintenance workers, Adams and Jones have worked full-time at the task, making repeated trips to the county's 179 schools.

For the most part they're successful, using a steam-blasting technique and odd concoctions of acid and other chemicals. The problem is the sense of deja vu Adams and Jones feel whenever they return to schools they have already cleaned.

"It's incredible," Adams said, sitting inside a bright yellow school maintenance van during a lunch break. "We can work hard all day getting the stuff cleaned from one wall, and come back the next day for a look and see the same graffiti sprayed all over the wall again."

The problem has become so acute this year that county schols launched an anti-graffiti campaign this month with the slogan, "Paint on our walls is egg on our face." The intent of the campaign is to create more community, faculty and student awarencess of the psychological and financial damage graffiti causes, according to J. Leonard Mullinix, director of school maintenance.

Adams and Jones think the campaign should have begun much sooner. "At some schools it's downright embarrassing the stuff they have on the walls," Adams said. "Like at Paint Branch High School and some other places, there's all kinds of KKK initials and racial slurs all over the walls."

"The problem I figure is that kids are bored or something and have to find some way to express their frustrations." Jones added, pointing toward a nearby lawn at the Potomac high school, where dozens of students sat beneath the noonday sun listening to rock music. "Plus," he said, "a can of spray paint costs only $1.49 at People's Drug."

Adams and Jones said they appreciated some of the graffiti they have cleaned. "Lots of it has to do with drugs," Jones said, gazing at an adjacent wall. "Cocaine, bongs [a king of smoking pipe], what have you. But sometimes you'll see a really nice portrait of a guitarist or really beautiful script that you just hate to clean."

"There's one high school in the county where somebody painted a really terrific ram on top of the school's smokestack," Adams said. "I don't know how he got up there to do it, but the school liked it so much they decided to leave it up there."

Styles of graffiti at other schools range from portraits of naked women to obscene limericks.

Laura McGill, a junior at Churchill, stood with a group of friends and watched as Adams and Jones meticulously swabbed each streak of graffiti with a syrupy brown acid.

"There's no need to take off 'The Hole,'" she said, referring to the name of a student meeting place at the school that was spray painted on a brick wall. "As long as it's clean why don't you let it be?"

Admas and Jones continued swabbing quietly until the students entered the building.

"It's hard, I tell you," Jones said. "Not only is it a futile job but we have to take razzing from the students sometimes. Either they're angry at us for cleaning up or they think we're undercover narcotics agents."

"Remember that girl at Walter Johnson?" Adams asked. "In spite of everything we told her, she still insisted we were narcs."

Adams and Jones then blasted the acid off the walls with steam, and watched the graffiti disappear as the wall dried. "Sandblasting tears the brick up," Adams said. "Steam and acid are a lot more time consuming but they get the job done."

The maintenance workers put the buckets and hoses inside the van, shut off the steam generator and drove to another section of the high school.

They expect to return to Winston Churchill, to the same walls and to much of the same graffiti, on their next monthly trip.