The idea of Peter Cook as Sherlock Holmes and Dudley Moore as Dr. Watson in a spoof of "The Hound of the Baskervilles" sounded fairly amusing. Since the movie was shot in England in 1977, its subsequent failure to be released invited speculation: How much of a dog could this undertaking have been?

The mystery has been cleared up for the intrepidly curious by the K-B chain, which plucked the Cook-Moore "Hound" from obscurity last weekend for unannounced bookings at the Cerberus 1 and Georgetown Square. A ponderous shambles, the picture adds no luster to the reputations of the co-stars, who also wrote the hodgepodge of sketches that substitute for a clever, sustained parodistic plot. The always dubious directing choice -- Paul Morrissey, who made his eccentric, checkered reputation as a comedy "stylist" by supervising the inert bohemian drollery of "Trash" and "Andy Warhol's Frankenstein" -- seems a death wish. Morrissey's lack of energy, timing and judgment condemns all but a handful of sequences to helpless paralysis.

Nevertheless, a fiasco that drew on the talents of performers like Cook, Moore, Griffith, Terry-Thomas, Joan Greenwood, Denholm Elliot, Kenneth Williams, Spike Milligan, Irene Handl and Roy Kinnear can't help but exert a certain fascination in retrospect.

The plot of the Conan Doyle classic serves as a vaguely recollected pretext for miscellaneous sketches, ranging from jokes about accommodations at murky Baskerville Hall to a gratuitous parody of supernatural shocks in "The Exorcist." Dr. Watson accompanies the new heir to the Baskerville estate -- the predecessor having turned up dead on the moors with the "footprints of an enormous, gigantic hound" nearby.

The only genuinely crowd-pleasing gag in the picture is an obscene groaner that goes over like gangbusters with kids. Elliot plays the owner of the neighboring estate, a man named Stapleton who breeds Chihuahuas. He places one little pet in the coat pocket of Watson. When the pocket starts to leak, Elliot extracts the naughty doggie, which keeps on leaking and leaking and leaking, subjecting poor Watson to a nonstop, mind-boggling spritz. Like the campfire scene in "Blazing Saddles" or the swimming-pool panic in "Caddyshack," the ceaselessly piddling Chihuahua in "Hound of the Baskerville" is such literal dirty joking that it can't miss provoking childish glee.

The most peculiar aspect of the arbitrary scenario is the insignificance of the Holmes role. Cook slips into the background while Moore runs himself ragged attempting to carry the decrepit show. The desperately busy Moore doubles as Sherlock Holmes' prattling, intimidating mum, a bogus medium named Ada. A pushy punster, she is typically exploited smacking a flunky and then quipping, "I like to strike a happy medium."

In addition to Watson and Mrs. Holmes, Moore also appears as a rumpled, inept piano player at the start and finish of the movie and also assumes the disguise of Mr. Spiggot, a one-legged man rejected for employment by Holmes in a scene that reworks an old Moore-Cook sketch. In case you've forgotten, the idea is that the potential employer tries to let the applicant down gently: "You're deficient in the leg division to the tune of one . . . I've got nothng against your right leg. The trouble is, neither have you . . . If I get no two-legged runners within, say, the next 18 months, you, a unidexter, will be the man for the job."

Cook's impersonation wouldn't justify a leading part for Holmes. In an interview two years ago Moore talked rather vaguely about the disappearance of "Hound," but claimed that he had played Watson as "a rather insane Welshman" while Cook was doing Holmes as "a Jewish tailor." The Welshman is identifiable, and Ada might make sense as a Jewish mother, but Cook's Jewish tailor would have been impossible to deduce.

This travesty Holmes is more of a slattern than an ethnic. Cook enters in a corset, hairnet and gaping dressing gown. He seems to be affecting a Liverpool accent with shades of an Elmer Fudd-Marthe Keller lisp. Holmmes and Watson never become an effective team. Watson takes charge of the investigation at Baskerville Hall, while Sherlock plays straight man to Ada back in London. Moore gets a duncey sidekick of his own in the awesomely silly form of Kenneth Williams, who flourished for years as the skinny, nasal twit in the "Carry On" series. The funniest line in the show exploits Willilams at his tailor-made, inimitable poofiest. Sharing a room at the mansion with Moore, who has just turned in for the night, Williams sucks in his already cadaverous cheeks, squints his eyes suggestively and purrs, "Ummmmm, I love your jim-jams, Watsy."

Willilams and a few other supporting players impose themselves fitfully despite the slack, enervated direction. Sloppy and disreputable as it is, "Hound" still preserves funnier fleeting faces and moments than you or the kids encountered at "The Private Eyes" with Tim Conway and Don Knotts. It's wreck, but it has a lot more raw talent to throw away.