If anyone's interested, I went ahead and wrote a VBS script that you can schedule to run on a nightly basis to clean up your WTV files.
It's pretty self-explanatory. Just modify the settings variables at the top of the file to specify your paths and time/days thresholds. You can also set it to either delete the files permanently or move them to another directory/path. You can then use the Windows "Task Scheduler" to schedule when to run and just point to where ever you saved the RTVHD-Cleanup.vbs file.
Download RTVHD-Cleanup.vbsJust let me know if you have any questions.
EDIT:
I added a logging feature so that you can have a history of what has been cleaned up and when (my wife's show that she never deletes):