Migration Planner converting files from 2003 to 2007 format

Does anyone know of a way to use the Migration Toolkit clean-up the
files it has converted?

I need to batch convert probably close to a million office files on
our network shares and I would prefer to do this where the converter
program cleans-up behind itself.

Using the Microsoft Office Migration Planning Manager toolkit, it does
a fairly good job at doing batch conversions of Office files, but it
makes a duplicate copy. So when it is done, you are left with ex:
"document.doc" & "document.docx"

I understand it is probably done in case the conversion loses some
formatting, but when you have to convert in the hundreds or thousands
to possibly a million files, you don't want duplicates.


Anyone else had this problem?

Thanks in advance.