"every scrap of knowledge" is a correct and usable phrase in written English.
You can use it to refer to a wealth of information, often implying that it is beneficial or useful in some way. For example: "He had worked hard to acquire every scrap of knowledge necessary for success."
He moved fluently from fiction to criticism, from light verse to short stories to the long-distance form of the novel: a literary decathlete in our age of electronic distraction and willful specialization, Victorian in his industriousness and almost blogger-like in his determination to turn every scrap of knowledge and experience into words.
Beginning in the 1960s, Mr. Lyles used every scrap of knowledge he had picked up on the studio lot to create low-budget westerns with well-known if slightly faded stars, turning out some 17, of them, none of which lost money.
I knew that his wife Eleanor was famously progressive, that when the African-American Marian Anderson was refused permission to sing to an integrated audience at Constitution Hall the First Lady arranged for her to sing on the steps of the Lincoln Memorial (an especially gratifying scrap of knowledge, this: it's not in the film!).
That latter fact has always seemed the most salient scrap of knowledge about Tom Waits's much mythologised background ("I was conceived one night in April 1949 at the Crossroads Motel in La Verne, amidst the broken bottle of Four Roses, the smouldering Lucky Strike, half a tuna salad sandwich…" and so on).
Yet I did love it, every scrap of it.
It notes every scrap of land and every debt and credit he holds.
The MRI scanner produces pictures of the insides of each captive, revealing every scrap of fat.
THE LAST BITE QI eat like a peasant, finishing every scrap of food on my plate.
We ate every scrap of it, and could only imagine it made with high-season tomatoes.
Every scrap of the animal was typically used: ears, snout, brains, feet and all.
The police love their screens: every scrap of information helps them to nab more criminals.
