Does computer duster show up on drug tests?

No, but it will kill you quick or give you severe brain damage so don't do it. People here ask what's the worst drug, and the usual answers are crack and meth. They're both fine candidates for the title of worst drug, but I'd say the very worst drug out there is spray paint followed closely by other inhalants, and then crack, meth, heroin, uppers, downers, all-arounders...