svn propset svn:ignore does not work if the target is a directory with a .svn folder

There are many tutorials that explain how to set svn to ignore a directory, such as:
Unfortunately, they do not mention that if you already have a .svn folder INSIDE the dir you want to ignore, it will keep showing up when you do an “SVN STAT” which can be fixed by just deleting the .svn folder that exists in the directory you want to ignore.