Expanding DiskCleanup to purge C:\windows\systemtemp on startup via Registry Edit?

Question

I need to delete files in C:\windows\systemtemp on startup. A blog indicated that I may be able to modify DiskCleanup by adding that path using these steps:

Just in case someone wants it. Add an extra folder to this registry path:

@ HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\VolumeCaches__Temporary Files__

"FileList"="." is already there, edit the REG_EXPAND_SZ "Folder" and add the path here.

If files are locked they will not be deleted as far as I know.

I can't find independent assurance this will work so I wanted to check here. Can DiskCleanup be used this way?