What ever became of clean money?

If you take a really definitive poll of, say, four or five people around your office, you're likely to find, as we have just done, that the most popular adjective for describing a dollar bill these days is ''shrinking.'' The deflated dollar has made everybody overlook an even more obvious defect. First and foremost, our shrinking bills are dirty -- sordid little rags that give the phrase ''filthy lucre'' a literal meaning.

Peer in your wallet or your purse -- if you dare. The look, and maybe the fragrance, of a mulch pile will greet you.

Remember when bank tellers dispensed nothing but clean, crisp bills, straight from the printing office to you? Now you're handed the sort of tattered refugees that you used to get only from pawn shops.

Any self-respecting consumer ought to be ashamed to be represented by such barely legal tender. Before they became the norm, one passed out worn bills only to undeserving waiters and rude toll booth collectors. Now one tries to palm them off on one's best friend.

Once the lonely cry, ''Can you change a five?'' used to produce a cast of Marcel Marceaus, patting their pockets and shaking their heads in mimed regret. Today the question draws a mob of strangers from blocks around, thrusting five disreputable strips of gray-green into your hands.

What can a fastidious person do? For those who will spend the time, there is always the challenge of rehabilitation. It is never too late for the youngish bill that has simply gotten off to a bad start - jammed any which way into a wallet or pocketbook. A skilled rehabilitator can fold back the dog ears and roll out the creases, finishing off with a smart smack. Except for lacking that certain first-time-only crackle, the bill will be as good as new.

But then there are the older bills that have suffered every humiliation grimy hand and lint-filled pocket can inflict. They have been crumpled, wadded, and stuffed into every nook and cranny imaginable. Loose change, chocolate raisins, and plastic combs have bruised and smeared them at every bounce of their owner's step.

Owner? Such careless stewards treat the bills in their custody with less regard than a traveling salesman treats a paper cup in a one-star motel.

And yet wonders can be worked in restoring even these victims of prolonged abuse. One stretches. One smoothes. One places the patient under a Webster's Third.

Still, there are limits. What can the most dedicated rehabilitator do with a bill that feels, and looks, like the frayed cuff of a work shirt? Your best efforts to pluck at the curled corners and edges only produce a fine dust under the fingernails. You settle for the center, but all you manage to do is to lend George Washington a despairing sneer.

What a gross end after a bright green beginning as a proud artifact of 75 percent cotton and 25 percent linen and a little fresh ink, accurately described by a nickname like ''lettuce''! Nothing can save this dilapidated thing that seems to be composed of potting soil and bacon grease, held together by cellophane tape.

It is at this low point that any bill-lover must ask: Where are the authorities? Why aren't these pathetic specimens taken out of circulation and put out of their misery?

The Wall Street Journal reports that a $250,000 currency-counting computer called the ''fitness defect detector'' is supposed to cull out all counterfeits and any ''mutilated'' bills sent to Federal Reserve banks, then mercilessly shred them. The remains are shipped to serve as landfill in New Jersey.

Knowing what the defect detector considers fit, we're ready to put up a few of our taxpayer's dirty dollars to buy a defect-detector detector.

We can live with imperfection, but until inflation is down to 6 percent and the dirty-dollar quotient is down to maybe one in five, we're going to figure that the American buck is in a currency crisis.