It was while watching the Dallas Cowboys on Monday night football three years ago that friends of Austin, Tex., businessman Noble Horace Dunson Jr. got an idea that Dunson turned into a multimillion-dollar sales gimmick for the drug paraphernalia industry.

As Dunson and "a bunch of good ole boys" shared a "hand-rolled cigarette," he recalled, they saw on the television Cowboy receiver Billy Joe DuPree, winded from a long touchdown run, place a plastic cone over his mouth and inhale oxygen.

"It was the inspiration for out first 'Power Hitter,'" Dunson said with pride of the trademarked device that is designed to enhance the effects of smoking marijuana.

The Power Hitter and its successor gimmicks also were the inspiration for Sen. Joseph R. Biden Jr. (D-Del.), and Sen. Charles McC. Mathias (R-Md.), as chairman and ranking minority member of the Senate criminal justice subcommittee, to schedule a series of hearings across the country on the issue of whether children are being lured into the drug culture by products designed to catch their attention.

Everyone seems to be talking about drug paraphernalia these days -- at the White House, in Congress, state legislatures, city and county councils, PTA meetings and ad hoc citizens groups -- but so far, litle has been done to curb the growth of what has become a $3-billion-a-year byproduct of the drug culture.

While the debate goes on unresolved, the mushrooming paraphernalia industry, in the finest tradition of free enterprise, is producing a stunning variety of ingenious devices to cultivate, prepare, inhale and ingest marijuana, cocaine and hashish.

The staples of the industry have been around for years: pipes, spoons, vials, boxes, scales, balances, needles, capsules and clips.

But it has taken entrepreneurs such as Dunson to conveive of "power Hitters" disguised as toy footballs, Frisbees, "Star Wars" space guns; roach clips for holding the butt ends of marijuana cigarettes that look like Mickey Mouse pins; pens and pencils and soft drink cans with secret compartments for stashing grass, and Chapstick vials that hide cocaine.

According to Peter B. Bensinger, administrator of the Justice Department's Drug Enforcement Administration (DEA), "this parisitic industry . . . operates perilously close to the line separating legal from illegal conduct, just to fill their pockets with extra dollars." Bensinger said 15,000 to 20,000 "head shops," and countless other retail outlets -- including drug and record stores and shopping mall boutiques -- have reached "epidemic levels," with annual sales approaching $3 billion.

L. Page Maccubbin, who operates a head shop, Earthworks, at 1724 20th St. NW, said he is tired of "self-righteous" crusaders picking on paraphernalia retailers as "scapegoats" for the drug problem. To close a shop such as his, he said, "is a move akin to amputation of a limb to cure a hangnail."

A number of early attempts to legislate against paraphernalia were struck down on appeal or rejected as unconstitutional by governors.

But Georgia, Indiana and North Dakota have enacted laws that are standing, as have the communities of Oyster Bay, N.Y., and Novi, Mich. And at the request of President Carter, the Justice Department has drafted model legislation that Bensinger said DEA's legal counsel "has assured me should survive even the most sophisticated legal attacks."

The difficulty in getting laws that will withstand court challenges results from the fact that many of the devices have legitimate uses. "Inatimate objects are neither good nor bad, lawful or unlawful," Bensinger admits. Criminality results from their use for illegal purposes.

Jill Gerstenfield, an attorney and drug abuse chairman of the Montgomery County Citizens for Education, helped write proposed legislation that State Sen. Margaret C. Schweinhaut (D-Montgomery) will sponsor in the Maryland General Assembly in January. The measure already has drawn 40 of the 48 state senators as cosponsors.

Gerstenfield told Mathias there is ample legal precedent for holding suppliers culpable for aiding customers in committing crimes, even if the articles sold have widespread legitimate uses. She said courts have held that sugar, rye, yeast, grape juice, rubbing alcohol and even a telephone answering service can contribute to criminal liability.

Biden, at a congressional hearing in Baltimore last week, expressed "a very serious concern" about gadgets designed to appeal to school children. But he said he was not convinced that all of the toys "are really for kids. I don't believe a Mickey Mouse pin encourages a 12-year-old to try marijuana," Biden said. The gadgets may be, as industry spokesmen contend, merely toys for adult drug users, Biden said.

Kenneth M. Bombard, who operates a "head shop" in Anne Arundel County, told Mathias that banning the exotic devices he sells in his shop will only cause drug users to turn to everyday articles such as toilet paper rolls, corn cob pipes and plastic catsup bottles.

"Drugs lead to paraphernalia," not the other way around, argued Bombard. He urged parents to "sit down and talk to your children . . . It makes me sick" to see parents using drugs, alcohol and pills, he said.

After he testified, Bombard was confronted in a hallway by another witness, Rhonda Leadbetter, a 17-year-old Severna Park high school senior, who said that as a former drug abuser she had purchased paraphernalia in his shop as a juvenile.

She testified that she began "smoking pot and dropping acid' as a seventh grader. She said she and her friends got the impression that "it must be OK, because the government allows paraphernalia to be sold."

Michael Pretzker, a Chicago lawyer who is legal counsel to the Accessories Trade Association, argued that "there is no such thing as drug paraphernalia, per se." He said Dunson's Power Hitter, for example, is "intrinsically a plastic squeeze bottle with a metal insert, designed for hand-rolled cigarettes."

State Sen. Schweinhaut, a white-haired grandmother of seven, stared at the industry representatives and said: "To think you'd take Christmas stocking (stuffed with paraphernalia and candy) to entice small children . . . I'm beyond words to express my dismay of such abuse of the free enterprise system."

Mathias said he is still uncertain what action the federal government should take, but he issued this warning to the industry representatives:

"Listen to the tone of these mothers. There is a storm brewing. You may have heard of Carrie Nation, who with her ax broke up a lot of saloons. I don't predict that, but there is precedent. You would be well advised to become self-regulators."