DOCFLORH00 - This is the header record for each route for a document. This is what shows up in the first screen after you click routing. The user is NOT set here, however these records could be deleted for a document if needed. There could possibly be multiple routes for a document if it's on multiple routes currently.
DOCFLOW00 - This is all the detail steps for a particular document route. If FFLOWSTAT = 'INPROCESS' where FFLOWUSER='USERNAME', the document will show in this users inbox. There will be one or more of these steps per route. If you reset the INPROCESS flag to ' ' you've effectively stopped the route in its tracks, so it will not show in anyone's inbox anymore for a route.
Clearing both files above resets ALL routes. Do with caution if there are routes in progress.
A more granular approach:
Identifying all documents in user TEST's inbox:
select * from docflow00 where fflowstat = 'INPROCESS' and fflowuser = 'TEST'
Clearing the INPROCESS flag for user TEST and essentially closing the route because it will no longer show in any inbox.
update docflow00 set fflowstat=' ' where fflowstat = 'INPROCESS' and fflowuser = 'TEST'