Hello Thomas,
I did quite a lot of mergers of contact persons. When I came into that project there was already a button active in contact person search result view when two contact persons were selected which navigated you to the data cleansing page. I don't know how that button was enabled. Maybe after you do the steps described in this document the button is available. In the DO_PREPARE_OUTPUT-method of that view where the other buttons are defined I can't find a hint about this button.
http://scn.sap.com/docs/DOC-34851
Best regards,
Thomas