If you want to clear junk from the added list of your T9 dictionary, check out the attached tool!
You can add and delete words into the dictionary and it works instantly - no reboot required, as it amends the T9 files on your device.
I've tested on the Diamond WM6.1. not sure about other devices, but it should work.
As to backup your T9 added words, copy the following files out somewhere:
\Windows\eT9Cdb.Cdb
\Windows\eT9Rudb.Rdb
\Windows\eT9AsDb.Adb
After hard-resetting/re-flashing/or even changing phones, just restore the files back into Windows.
Cheers
Diamond