Congress relishes another franking privilege : Meat lobby puts on the dog with exclusive luncheon for lawmakers--experts on pork.

From the outside, it might have been an intimate afternoon cocktail soiree for some distinguished head of state. One hundred lawmakers and their families. By invitation only. Press secretaries must be accompanied by a member of Congress. Guest passes not transferable.

But inside it was just a bunch of lawmakers stuffing foot-longs in their faces, thinking of patriotic musings about hot dogs and contemplating one of life’s great mysteries: Why do they sell weenies in packs of 10 and buns in packs of eight?

“If you were born and raised in America, if you ever heard about America, if you came to America after you were born, you gotta love hot dogs,” Rep. Austin J. Murphy (D-Pa.) declared before devouring a traditional with mustard and relish, a red Hebrew National cap on his head.

The Hot Dog Lunch of 1994 has become the social ticket of the summer. OK, so that’s a slight exaggeration. But they were turning them away at the door Wednesday in a Capitol Hill courtyard where the American Meat Institute served up hundreds of free hot dogs and sodas in an effort to remind Congress of a great American institution.

The uninvited were flashing congressional passes and begging to get in. One man said he absolutely had to clean the courtyard fountain. And why wouldn’t it go over big? This party combined two of Congress’ most affectionately held institutions: pork and a free lunch.

“Hi, congressman. We got all-beef, low-fat,” someone from OhSe Foods of Topeka, Kan., told Rep. John J. (Jimmy) Duncan Jr. (R-Tenn.).

“I don’t eat anything fat-free,” said the congressman, who used to be a batboy and knows his way around a hot dog.

“Well, this has some fat in it,” the hot dog man replied, eager to put the dog’s best foot forward, it being National Hot Dog Month and all.

This was more than just food. It was a cultural experience. And this was more than just lunch. It was lobbying in a bun. Not since the ice cream freebie had buttonholing been such fun.

“This is our chance to highlight the meat and poultry industry. This is the one big event we do, “ Meat Institute spokeswoman Janet Riley said.

It wasn’t a perfect day. There was some concern that the humans inhabiting the Arnie the Hot Dog and Smiley the Pig suits might pass out in the searing heat. And President Clinton failed to show up again, his nametag left unpinned on the greeting table.

Otherwise, the meat industry seemed to be preaching to the converted. Congressmen gleefully wolfed down every imaginable version of the hot dog--smoked kielbasas, jumbo grillers, Big & Juicy’s, kosher dogs and spiced dogs--topped with every imaginable condiment--hot mustard, sweet mustard, jalapenos, spaghetti sauce, regular relish, corn relish, maple syrup salsa and the secret sauce of Rep. Jack Kingston (R-Ga.). (“If I told you the recipe,” an aide explained, “I’d have to shoot you.”)

The Meat Institute crew worked to debunk the popularly held notion that hot dogs will kill you faster than movie popcorn or nachos.

“That’s the urban myth,” Riley said. “Hot dogs are made from trimmings, which come from perfectly good cuts of meat. If they use liver or kidney . . . it will say ‘variety meats’ on the package. Otherwise it’s whole muscle meat.”

Yummie.

Several congressman got quite involved in the event, even submitting their favorite hot dog recipes, which were assembled into “The Congressional Hot Dog Recipe Book: the Private Hot Dog Recipes of Members of Congress.” Contributions from ever-health-conscious California were conspicuously absent, although it is said that Sen. Barbara Boxer (D-Calif.) once submitted the San FranKcisco, which called for sprouts.

For those not seduced by the dogs, there were former baseball players Jim (Catfish) Hunter, Warren Spahn, Bobby Thomson and Jim Bouton on hand to sign free baseballs.

All in all, the meat industry made its point. A good hot dog is hard to resist, although the less one thinks about the ingredients, the better. As one news photographer put it, beholding the last bite of her Hebrew National: “We’re all gonna die anyway.”