If you want to do it more surgically and remove specific fields (leaving others, like seek tool data, etc. intact) there is code in emphatic to munge hda3 data and make sure the checksum is valid afterwards (which is necessary.) This may even allow you to make sure the play count isn't random. I'm moving to mp3fid/rsync myself, and may take this challenge on if you don't beat me to it, but if you'd like me to point you at the specific parts where I'm doing this type of stuff, let me know.