How to delete tracks from Rekordbox & dropbox cloud sync

I am trying to delete some tracks from my Rekordbox but I want them to also be deleted from my Dropbox cloud sync. What I have done so far is I created a myTag called delete, then created a smart playlist for that folder. I have about 600+ I want to delete but not sure what is the best way to do it. I tried editing all of the tracks at the same time in the delete folder and then I went to the Rekordbox folder in dropbox, sorted the tracks by date modified but the tracks are not appearing as the most recent tracks modified. Please help. Thanks