Summary: Lestrade may be baffled, but it'll all come out in the wash.
Inspired by Small Hobbit's The Bogus Laundry Affair
He is a big, powerful chap, clean-shaven, and very swarthy— something like Aldridge, who helped us in the bogus laundry affair. – Lestrade's letter to Sherlock Holmes, The Adventure of the Cardboard Box.
"Surely it's obvious where the drugs were being distributed?" Sherlock announces, and Lestrade somehow doesn't yell at him. They found the body of Aldridge, the Drug Squad's informant, twelve hours ago, and Sherlock is his last hope.
"It can't be Forster Street," he says patiently. "Pub's been watched for a fortnight, and it's clean. Aldridge must have been stringing them along."
"Of course it's not the Ferret and Fudge," Sherlock exclaims, "Why would anyone think that? This was bulk distribution, Lestrade. The collectors had to be able to take substantial packages away unobtrusively. Which is why you should be investigating the Speedy Laundry Co at the other end of Forster Street."
"A bogus laundry company?"
"You'd be amazed at how much cocaine you can hide in a duvet cover." A frown from John, standing beside Sherlock. Bet he'll be checking 221B's airing cupboard when he gets home.
"It's possible," Lestrade tells Sherlock. "But we've got no evidence that Aldridge ever used the laundry."
"Haven't we? Describe the man."
"Big bloke, black hair, dark complexion–"
"–It wasn't a dark complexion, but ingrained grime," Sherlock breaks in. "You smell, but you do not observe. The dead man's body was filthy, yet his clothes reeked of fabric conditioner. We're looking for a murderer, Lestrade, who has access to large quantities of Lenor Summer Breeze."
Note: Small Hobbit has also now written a longer ACD case based on the reference: The Case of the Bogus Laundry.