This does work just fine since OS X is a certified UNIX but the problem is that when you delete the app by drawing it to the trash, there is no way to know if that particular developer has dropped off any files in the classic UNIX file system on your machine. Since OS X is based on UNIX, app developers have slid back to the old days and use the old UNIX directory locations to store preference files, settings, licenses, etc. We still have the same trivially simple mechanism for OS X but there is now a glitch. In the classic Mac days, from System 1 to System 9 this worked perfectly well. Uninstalling software on a Mac is a trivially simple process, you drag the app in question to the Trash can and you are done. No I would gently tell them, if you don’t know how two clean your Mac now, then using a third party tool to uninstall leftover software pieces would just make that process even more random.
It was a often repeated ritual, I would go to my friend’s house and they would ask me if they needed to buy Spring Cleaning for their Mac.
