Are you confident that it doesn't appear anywhere else? There's two main concerns: the first being that you use a URL differently---and think of it differently

Are you confident that it doesn't appear anywhere else? There's two main concerns: the first being that you use a URL differently---and think of it differently---than a password; and the URL persists in various forms. Accessing a resource on the Web might be logged in numerous places---e.g. your web history and internal network logs or MITM if not over https---and might be sent as metadata, like a referer header to another website. Imagine if all of your passwords were logged by your client any time you entered them in.