Maybe off-topic to the original question, but you could also use the Global Inbox in Save Dialogs add-on to get stuff into DEVONthink as a move instead copying:
I personally only use an alias I created for the global inbox on my desktop to move stuff into DT.
The path is below:
Right-click the Inbox and make an alias, which you can then drag to the desktop or anywhere else. I added a nice icon and it looks like this on my desktop:
