I do the knocking out of habit, but my boy really doesn't need it.

Can take time, but eventually (if lucky) you'll have an animal that you won't need to use the hook with and will be ready for handling due to certain cues you're giving it vs "feeding time". Mine can tell the difference due to things like "rat smell, enclosure top left open" vs "no rat smell, enclosure top closed, knocked on". They're smart enough to differentiate.