E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Slip-slop, wish-wash, twaddle, talk about gruel. Skilly is prison-gruel or, more strictly speaking, the water in which meat has been boiled thickened with oatmeal. Broth served on board the hulks to convicts is called skilly.
It is the policy of Cursitor Street and skilly golee.The Daily Telegraph.