The Short Version
The claim captures a real element of Billig's thought but overgeneralizes it in ways that distort his framework. Billig's thesis about ideology operating through unnoticed, taken-for-granted mechanisms is developed specifically in the context of "banal nationalism," not as a universal theory of ideology. His earlier work (Ideological Dilemmas, 1988) emphasizes that ideology also involves contradictions people actively articulate in everyday talk, which complicates the claim that ideology works "most effectively" when unnoticed.