Good question. I'm not sure I'd ever use that phrase (not that I don't trust anyone enough to trust them with my life). I think the phrase is common/cliched enough that I could probably use it without having to think about its grammatical construction, if that makes sense. There are many such phrases that I (and others) use to convey the standard meaning of said phrases without stopping to think about why those words coupled together mean what they do. However, should I decide to reconstruct your example, I think I would go with your latter suggestion.