How do you know what's actually there so you're not off on a wild goose chase for a book that has already been caught?
The "go hunting" pages can help you see where books have been released recently, but they can't guarantee that the books will still be at the release spot. Book-swap shelves, including Official BookCrossing Zones, Little Free Libraries, phone-box swap-shelves, etc. may tend to have larger stocks of books at any given time, but even then the listings probably aren't accurate. Many people do take the books without journaling right away, and while those books may be journaled eventually, in the meantime they'll continue to show on the hunting pages.
[I have noticed that some book-swap-shelf managers keep a tighter inventory than others, checking the shelves themselves and changing the status of books that are missing, but this takes a lot of time and effort, and I don't know how many shelves have managers who are interested in this level of maintenance.]
Book-hunting is more of a fishing trip than a visit to the library: you might find something, or you might just have an interesting trip. You can plan to drop a book or two of your own at the spots where you're going hunting; that way, whether you find any books or not, someone else who's visiting those spots might find yours.
One feature that you might find handy: the "manage release alerts" option under the "home" tab lets you subscribe to email alerts for specific towns, and when any books are wild-released there you'll get an email summary listing them. Since the emails come out once a day, this might be too late for you to find specific titles, and you might find it easier to just bookmark the hunting pages for areas near you and check them before you're planning on going out, but the email alerts can come in handy sometimes. But, again, there are no guarantees - sometimes the person making the release notes accidentally enters the wrong information, and the book never appears at that spot at all.