[Puppet Users] Delete "unmanaged" files in directory

Hello readers,

I might have the need for something like "delete all unmanaged files".
Explanation: I am creating a bunch of apache config files, which contain
information about the hostname and the port they're listening on. Now if I
change the host name - or the port - the last generated file keeps sitting
there, and does nothing in the best case (rarely ;), and provokes errors in
all others.

Now because _all_ config files in those directories are generated by me &
puppet I wondered if there's a method to find out which files are _not_
genereated by puppet, and simply delete them.

Any ideas, anyone? :)
Thanks in advance,
Axel.