Yes, a lot of people seem to think it will help to hang them. But they were really designed as an alternative to hanging. I don't know where you were hiking, it's probably not a real issue in a lot of areas - it struck me after I posted that most people who get the bear canister are doing so because of some regulation but that isn't necessarily true of you. Some do get them because they are that concerned. It probably would have been more of an issue in an area where bear canisters are actually required, as those are generally areas where hanging is no longer effective.

I also run into a lot of folks who are afraid of black bears - even the habituated ones who are no longer afraid of people will run away if you yell and wave and carry on at them. It's not unheard of for them to be aggressive, but more rare than for brown bears. Maybe that's not really reassuring for your wife, it didn't reassure some of the folks in my hiking group either but in most areas it's not really going to be a problem. They just like your food as much as you do.