If you don’t use dwell clicking but would still like a repeating drag and drop capability, here is a script that uses an extra mouse or trackball button to toggle repeating drag locks on and off, for moving tiles in Words With Friends.
#IfWinActive, Words With Friends on Facebook – Mozilla Firefox
; Allow multiple threads so that this hotkey can “turn itself off”:
if drag_drop = y
drag_drop = n ; Signal the other thread to stop.
drag_drop = y
if drag_drop = n
Click down LButton
Click up LButton