The tool should update Facebook's cache for a given URL immediately, if Facebook is still returning 'stale' data, check that Facebook is actually getting the content you're expecting.
A quick way to check is to load your page from a command line tool like curl, using Facebook's user agent and see if the meta tags returned are what you were expecting.
One thing i've seen happen sometimes is people including all the correct tags on page X, except that page X has an og:url meta tag pointing to another url, Y.
Facebook will follow that tag and scrape page Y and use that metadata.
I've usually seen it where page X is 'something.com/article/x' and the og:url is set to 'something.com/articles/' or 'something.com'