filter clean leaves uncommitted file

So, I want a way of sharing parts of a gitconfig organizationally, so I change and comment out some parts with a filter:

[filter "gitconfig-rmuser"]
  clean = sed -e \"s/^\\( *email =\\).*/\\1 <email address>/\" -e
\"s/^\\( *name =\\).*/\\1 <real name>/\" -e \"s/^\\( *signingkey
=\\).*/\\1 <gpg key>/\"

And then:
$ cat .gitattributes
* filter=ident-line
gitconfig filter=gitconfig-rmuser

Which works. The only problem is that if I change it again after the commit, I get: $ git status # HEAD detached at e872204 # Changes not staged for commit: # modified: gitconfig # no changes added to commit $ git diff gitconfig $

So the repo remains dirty and I can't do anything with it.