[PaulWay] You are almost correct. Face Pyjamas was a kind of euphemism game, as originally conceived, and as I tried to make clear in my initial move, above. But some seem to have found the concept impossible to comprehend, and it's now a sort of MC Dictionary.

Folly Bucket - the polite name for a device originally invented in Geneva, Switzerland, as a sort of portable vomitarium cum chamber pot for young bloods intent on getting helplessly drunk without sullying the pristine streets. The term is now used to describe the sort of person who ought to carry one.

Velvet Scabbard

I think I overheard someone explaining that one at work today; it's the term for some piece of 'assistance' rendered by management to employees that is supposed to save time and money but is actually practically useless. E.g. "I wanted a sword and he gave me a velvet scabbard." The velvet bit refers, I think, to the fact that management find these things quite attractive in a "buzzwords and warm glows" way.

I've got one for you: Pudding elbow

Embarrassment caused by over-reaching oneself. Derived from the fate of those who, in reaching for the cream, dangle their sleeves in the Charlotte Russe.

Cornish Date?

This is a thing rather like a haggis, but instead of wholesome meat and vegetables it's filled with dried fruit. It was originally made for tin miners to take to work as a kind of packed lunch, the rationale being that it was so revolting it would make working in a tin mine seem not so bad after all.

An acquaintance asked if I want to try salty surfing. Do I need a licence?

This is simply another name for bodysurfing, where you use yourself as the board. More salt in the face, you see.

What do you think of a round of foot crepes?

No thanks. Those large, round discs of dead skin from the soles of your feet are hard to make palatable.

Purple lampoon?

As I see it, it's a guy sharking after hours in Cleveland.

I've heard this one but not sure of its meaning: A frayed rope in the pulley.

It's applied to chaps who (ahem) can't get IT up. IT, or Information Technology, is quite a complex undertaking and a broken wire (frayed rope) in the circuit (the pulley) will just prevent the user getting it working (up).

Safari Beard

The results of a night in the bush.

Ahem.

I've heard of a Toilet Duck, but what is a Pantry Chicken?

Ah the Pantry Chicken is that strange little beast that lurks in the larder, but whose existence it is impossible to prove. It is responsible for mysterious crumbs where there used to be cakes. For scuffling, scuttling noises heard on opening the door suddenly. For any strange noises heard through the closed door. And most notably for the fact that eggs - that turn out to be hopelessly addled - turn up in the most unlikely places.
The chicken itself of course is mythical, but it is used to explain any of the above (and many other) inexplicable phenomena involving this store room.

I once overheard an elderly pair of ladies discussing Pimlico pasties - any ideas ?

It's difficult to tell the context from your question, but if the ladies seemed to be the kind of elderly ladies who enjoy their food, then they were probably referring to savoury filled pastry snacks. Pimlico pasties, in particular, are characterised by a generous admixture of horsemeat (Pimlico being a racecourse in Maryland, USA). On the other hand, if the ladies still looked in fine fettle, slim and a little cheeky, they may have been referring to that variation on the glittery stick-on pastie used by strip artistes as a rather vestigial modesty aid - a tip of the hat, if you like, to covering at least one goose pimple - the Pimlico Pastie, made entirely of cellophane.

Stiff Gallop?

I think you misspelt it. A Stiff Gallup is a election/poll/whatever in which all of the choices are equal given the margin of error. So named because it was said that deadlocked votes were the only means of excitement for Mr Gallup.

Tuna Harbour

The semi-mythical Tuna Harbour is a massive 'C'-shaped formation of rocks, just below the surface of the Pacific Ocean, which is possibly the remnants of a long-extinct underwater volcano. As such, the composition of the rocks are such that marine life thrives there, and hordes of tuna descend upon the place daily to feed. Canny Hawaiian fishermen have sussed this out, and are known to make frequent nocturnal trips to Tuna Harbour, where a little effort guarantees great satisfaction.

I heard that a friend of mine was caught polishing the yucca. Is this serious? (And do I win £10?)

Very serious. Though it sounds like simple hanky panky (if you know what I mean), it is, in fact, much more serious. It concerns the fraudulent filling in of email addresses when requested by websites. This may seem pretty innocuous, until you realise what damage is done by perpetuating false email addresses. Think of the vast quantities of important advertising email that is sent to bogus recipients. Think of the plight of African victims of oppression who have several million dollars to move to the West, and can't find anyone trustworthy to help. Think of all the poor devils who need parts of their bodies enlarged, or access to life-saving drugs like Viagra. And think how email-spoofing behaviour is harming all these wonderful enterprises. The name is derived from the unfortunate Yukka Polish Inc, which pre-dated the internet. They send out their adverts in these handy reply-paid inserts that you just love to find in magazines, but to which some twisted pervert of a DJ on The Light Programme of the BBC took an unaccountable dislike. He recommended that listeners fill in the reply with a bogus name and address and send it back. The resulting postage-paid bill would have sunk the company anyway, had not the weight of accumulated mailbags not caused the company HQ (a portakabin) to slide into Portsmouth docks with the loss of all hands.

Try something less vicious, like the Belfast Sandwich

What did I say that stopped the game dead?

Dunno, Gil - I thought it would be cheeky if I posted again so soon on this one!

They say the best things come to those who wait.

Oh. I thought it might have been the double negative in the last sentence.

A Belfast Sandwich refers to any foodstuff which causes highly explosive flatulence - as eloquently expressed in the well known saying, "Those globe artichokes make me fart like a Belfast Sandwich."

While I'm getting my coat, does anyone know what a Tavistock Kevin is?

Oh yes. Kevin Tavistock ("Kevin t' hav' 'is stock"; shown as Tavistock Kevin) is a fake sender name filled in by automatically propagating spamming worms. If you recall the Weebl & Bob episode "Bob Goes To France Part 3", you'll recall that Kevin was a transvestite French stripper that stole Bob's kidneys. The e-mailed name gives reference to that; the contents of the spam are for smuggled organs.

Anyone ever hear this one, popular in Maryland: Frightened pink terrapin ?

[Frightened pink terrapin ] Nope. That's a new one on me. On the other hand, you may have been fooled by the rather broad Maryland accent. Could you have been hearing, instead, "Heightened sink tarpaulin", a device for preventing one's washbasin from being invaded by what the locals, for tourism reasons, like to call "pine bugs", but are, in fact, massive, rapacious, fast reproducing, genetically modified cockroaches with very loud voices.

What's it mean when someone is referred to as a bit of an Andogynous Andrew.