The Kingdoms very own Victor Meldrew here.....

If the kids (or adults) say 'trick or treat' at the door, I remind them that they are Scots and the proper term is Guising and was on the go loooong before the americanised version.
They earn their goodies up here rather than being more of the 'pay up or else' that kinda symbolises the U.S. culture.

From wikipedia....
Guising
In Scotland and Ireland, "guising" — children going from house to house in disguise — is traditional, and a gift in the form of food, coins or "apples or nuts for the Halloween party" (in more recent times chocolate) is given out to the children dressed up in various costumes.[33][34] The tradition is called "guising" because of the disguises or costumes worn by the children.[35] In the West Mid Scots dialect, guising is known as "galoshans".[36] Among the earliest record of Guising at Halloween in Scotland is in 1895, where masqueraders in disguise carrying lanterns made out of scooped out turnips, visit homes to be rewarded with cakes, fruit and money.[2] Guising also involved going to wealthy homes, and in the 1920s, boys went guising at Halloween up to the affluent Thorntonhall, South Lanarkshire.[37] An account of guising in the 1950s in Ardrossan, North Ayrshire, records a child receiving 12 shillings and sixpence having knocked on doors throughout the neighborhood and performed.[31] There is a significant difference from the way the practice has developed in North America with the jocular threat. In Scotland and Ireland, the children are only supposed to receive treats if they perform for the households they go to. This normally takes the form of singing a song or reciting a joke or a funny poem which the child has memorized before setting out.[31] Occasionally a more talented child may do card tricks, play the mouth organ, or something even more impressive, but most children will earn plenty of treats even with something very simple. Often they won't even need to perform.[33] While going from door to door in disguise has remained popular among Scots and Irish at Halloween, saying "trick-or-treat" has become common.