No one can say the Iran-contra hearings were for naught once they see "Shredding Party," Harry Shearer's pricelessly funny new music video derived from such exchanges at the hearings as:

"What did he tell you about a shredding party?" -- Arthur Liman. "Well, just that there had to be one." -- Robert McFarlane.

Three Marines dance into, out of and across footage from the hearings, some of it impressively recent, while a chorus sings the catchy "Shredding Party" refrain. The video is the third segment and easily the highlight of "This Week Indoors," a new "Cinemax Comedy Experiment" that premieres on Cinemax, the pay cable service, at 10:30 tomorrow night.

It plays again July 22, 25, 27 and 31.

The pilot for a comedy magazine of the air, "Indoors" attempts to merge, or at least alternate, the talents of Shearer with those, less easily defined, of Merrill Markoe, former head writer on "Late Night With David Letterman." Unfortunately, most of Markoe's segments play like marked-down Letterman. In the most embarrassingly derivative one, she lectures her two dogs on proper behavior in the home.

She's trying to do the "found comedy" she helped Letterman perfect. Trouble is, she doesn't find much. A visit with two transvestites as they dress backstage has considerable unexpected charm, however.

Markoe's real problem is that she appears in all her segments, and less camera presence than hers it would be hard to have. John Poindexter has more. Margaret Heckler has more. Merrill Markoe's two dogs have more. She is a very fresh writer with absolutely no future as a TV personality.

Shearer isn't exactly scintillating, either, except he has the sense to dress up in droll disguise -- first as a blubber-faced Jerry Falwell in a duncey religious debate show, "At Loggerheads," opposite Russ Parr's expert impression of Jesse Jackson. "We must use progress as an ingress to success, not regress for an occasional excess," Jackson says.

The half-hour closes with "Hellcats of the White House," a video version of a caustic regular feature on Shearer's L.A. radio satire show. Even though he is about two feet too short for the part, Shearer makes a hale Ronald Reagan. While Nancy Reagan (Julie Payne) sands dry skin off her neck and elbows, the president parries with a worried Mike Deaver (Tom Leopold).

Once Deaver leaves, Nancy says, "Ronnie, we've got to dump him like last week's fish." And Ronnie says, "Come here, kiddo; you're always so warm after sanding." Crude and even mean perhaps, but the scene puts that lame and frantic puppet satire, "Spitting Image," to shame, and to rest.

The "Cinemax Comedy Experiment" continues to have, for television, an admirable record of public service. Shearer's segments on "This Week Indoors" rank with the series' best: "The History of White People in America," the Gilbert Gottfried special and Chris Elliott's "Action Family."

Markoe's, alas, have more in common with such classically unsuccessful "Experiments" as Paul Shaffer's "Viva Shaf Vegas," one of the biggest bombs ever detonated in the Nevada desert.

'Karen's Song' Patty Duke gives real dignity to the word cute. And she is cute even when playing a worried 40-year-old in the new Fox sitcom "Karen's Song." But ennobling the show itself is beyond even her. Hepburn in her prime couldn't save it. Six elephants trained to walk a tightrope would have their work cut out for them.

In the series, which premieres at 9:30 tonight on Channel 5, Duke plays Karen Matthews, who just as she turns 40 finds herself enamored of a 28-year-old man played by likable but blurred Lewis Smith. Matthews' 18-year-old daughter (Terri Hatcher) is shocked. Her sassy pal Claire (Lainie Kazan, one of the few true grande dames) is titillated. And so on.

Fact of the matter is, Karen Matthews is so dull she makes Molly Dodd seem electrifying.

Perhaps judging the new Fox shows even by the minimal standards of normal network fare is harsh. They don't seem to be attempting to be funny, or clever, or original; only to target and fondle particular demographic segments of the audience. Women, or men, who are having midlife crises or who have taken younger romantic partners may find "Karen's Song" plucks an adequate number of responsive chords.

But people looking for entertainment will come up empty. As for Duke, someone ought to cast her in "The Barbara Walters Story" before she gets any older. She looks a lot like Walters, and she has a voice reminiscent of the young Martha Raye. She deserves better than "Karen's Song." Everybody does.

'Beans Baxter' However old you are, chances are you are either too old, or too young, for "The New Adventures of Beans Baxter," a childishly whimsical adventure series from Fox TV premiering at 8 tonight on Channel 5.

The hero is a spindly 16-year-old who enters the espionage racket after his father, an undercover mailman, is kidnaped by slapstick terrorists. Beans, played agreeably by Jonathan Ward (of last season's whiny "Heart of the City"), is your average nerdy kid who, before he leaves Witches Creek, Kan., for a new home in Washington, D.C., tells his girlfriend, "I am cuckoo-for-Cocoa-Puffs over you."

No, a Charles Boyer he ain't. But then, the audience to whom "Beans" is addressed wouldn't know Charles Boyer from Pee-wee Herman.

In a Washington that looks nothing like Washington, Beans attends "Georgetown High" and, immediately upon arrival, gets a new girlfriend, this one named Cake Lase (Karen Mistal), which strangely doesn't prompt any "cake" jokes, and won't here, either. It takes a long time for Beans to realize what's what in this premise-establishing premiere, but as there are few adventure shows for kids any more, the audience may be quite patient about getting to the meager payoffs.

As an homage to, or a steal from, "Get Smart," secret agents live in post boxes or cigarette machines; they all seem to speak with the (unbilled) voice of actor Richard Mulligan. And as a sop to adults, the episode closes with variations on the last scene in "Casablanca," not that that hasn't been done 10,000 times before.

"Beans" was written, directed and executive-produced by Savage Steve Holland, a witless drudge with a few definitely dreadful movies to his credit.

Once it assumes its regular half-hour length (starting next week), the show may have a brisker tempo and offer less opportunity for daydreaming, channel switching or composing a classified ad with which to sell one's TV set. To end on a positive note, television does get worse than "Beans Baxter." Not much, and not often, but it does.