An invigorating herbal and medicinal drink which has marked restorative effects on the consumer. Known for centuries in Überwald, any Igor worth his stitches knows the secret, and will happily brew a cup for a Marthter who is tired and in need of relaxation at the end of a long day. There is no alcohol in it whatsoever, partly because alcohol cannot survive the company of the other ingredients, which Igor will vaguely define as "tree-bark". If pressed, Igor will also refer to "naturally occurring mineral salts", and then smoothly inform you that in Überwald, nothing gets a man out of bed in the morning and out working in six feet of snow to hammer through the plug of ice in the well faster than a mug of hot Splot.
It's just a shame that the human speech faculty cannot keep up with the surging thoughts and bright sparkly new ideas running through a Splot-permeated brain.
Later on, you may discover that belladonna is a herb, and arsenic salts are indeed a naturally occurring mineral.
It has been alleged that absinthe and Fernet-Branca are the nearest Roundworld equivalents, although both bear the same relationship to Splot that Nanny Ogg's original recipes do to the published versions. They are also alcoholic drinks, which Splot explicitly is not.