I wouldn’t dare do this now but sometime prior to 9/11, I flew round trip from Washington National to Houston International and had forgotten that my carryon contained a battered Swiss Army knife. The screeners at National paused when checking my carryon, I can only assume it was the knife that got their attention and they were deciding what to do about it. They eventually let me proceed with no problem.
That knife was still there on the return trip. The screeners in Houston had no problem whatsoever.